Doxology or Devil - The debate over the ending of the Lord's Prayer

In an article in the Puritan Reformed Journal (2021), "Doxology or Devil: A Case for the Longer Ending of the Lord's Prayer," OPC Pastors Brett Mahlen and Christian McShaffrey provided an attempt to defend the reading of Matthew 6:13 found in the King James Version, though not as the main text reading most recent major English translations.  Subsequently, they were interviewed by pastor Jeff Riddle (not OPC) for what I believe is his vlog on this particular topic (link to article)(link to video).  As I've recently had a video episode on the same topic without the benefit of having heard the presentation of Mssrs. Mahlen, McShaffrey, and Riddle (MMR), I thought it prudent to provide a few comments on the material they provide.  I refer to MMR throughout, whether referring to the article that didn't include Riddle, or the video, which did.

The article begins with an important concession, namely that the question of whether "for thine is the kingdom, and the power, and the glory, for ever. Amen" is original is a question that obtains its answer through textual criticism.  They specifically admit: "That is a question that can only be answered through textual criticism." (p. 21)

Unfortunately, the rest of the article does not pass textual critical muster.  The arguments may be summarized as follows: (1) a rejection of the "shorter is better" principle of textual criticism; (2) an analysis of the internal evidence; (3) thematic considerations (a second category of internal evidence); (4) Greek manuscripts; (5) Other Ancient Witnesses (a first category of external evidence); (6) Liturgical Use (a second category of external evidence); (7) Roman Catholic Usage (a third category of external evidence); (8) Reformation era usage (a fourth category of external evidence); (9) textual reconstruction (an argument about/against Westcott and Hort); (10) tomorrow's text (some discussions about the future of the text in light of the coherence-based genealogical method).

It's not clear whether MMR understand the "shorter is better" principle. As explained by Jeff Miller ("Breaking the Rules: Lectio Brevior Potior and New Testament Textual Criticism"), this principle of textual criticism originated with Johann J.  Griesbach (who died in 1812, before Brooke Foss Westcott's birth in 1825).  Miller goes on to explain that this principle is more of a description than a prescription.  Today, we might call it a rule of thumb.

Worse for MMR, Miller points out that this principle has been essentially abandoned by contemporary textual criticism, despite its presence in relatively recent descriptions of textual criticism.  While shorter readings are often still preferred over longer readings, it is not simply on the grounds that they are shorter.  

MMR argue that the principle is "based on the assumption that ancient copyists were more prone to add material to Scripture than accidentally omit." (p. 22)  MMR challenge this on the basis that they believe ancient scribes would have been worried about the warnings of Revelation 22:18 against additions.

Let's consider the Revelation 22:18 point first.  If MMR are right that essentially the TR reading of Revelation 22 is original, while Revelation 22:18 provides a warning against additions, Revelation 22:19 provides an even stronger warning against subtractions.  Adding (per vs. 18) will result in plagues, but removing (per vs. 19) will result in a loss of heaven itself.  Assuming scribes were concerned by Revelation 22's warnings, it would have been rational for them to err on the side of addition rather than subtraction.

Moreover, we may rightly question whether scribes interpreted Revelation 22 to be referring to all of Scripture or only the book of Revelation itself.  However, even assuming they interpreted it as applying to all of Scripture, the warnings favor a strategy of erring on the side of addition rather than on the side of subtraction: better to receive a plague than to lose one's place in heaven.

There is, however, a still more fundamental error in MMR's response.  The question is not whether scribes are more likely to deliberately expand the text or accidentally reduce the text.  The question is what scenario best explains the omission or insertion of text at this point.

In many cases, accidental omission is the most obvious explanation of a textual variant, particularly when the omission starts after a series of letters that are the same as the last few letters of the omitted material, and when the amount of omitted material is relatively short (less than a few lines).  Other cases where accidental omission are fairly certain are when the omitted word or letter renders the sentence or word meaningless or contextually nonsensical.  

This particular variant does not fall neatly into either of those categories.  

There is another option.  Another case where accidental omission might be expected to occur would be when there is some parallel verse (for example, in the synoptic gospels) that the scribe may have in mind and consequently may accidentally reproduce from memory of the parallel, rather than from the scribe's exemplar.    

In this case, the parallel account is in Luke's gospel, and there indisputably the Lord's prayer ends without the traditional doxology (see Luke 11:4).  So, one could imagine a scribe more familiar with the reading in Luke who might therefore truncate Matthew's version to conform to his memory.

There are a few problems with this, primarily that there is no reason at all to suppose the Luke's account would have a priority of memory for a scribe copying Matthew.  Secondarily, there is an observed tendency of scribes to be conservative of the text, meaning that they are more reluctant to remove something that they think is extraneous than they are to include something that think might be extraneous.  These suspected insertions were sometimes labelled with markings (see this discussion).  The same or similar markings were apparently sometimes used to separate the main text from marginal notes.  It is not hard to understand how a copyist failing to transcribe these markings could create a copy that shows material as main text material, where his exemplar had the material marked off.  It is thought that this could explain the suspected insertion at John 5:4 regarding the angel troubling the waters.

The accidental inclusion of the doxology into the text would be expected to occur because of a scribe inserting a doxology in liturgical use into the text, either from memory, as part of a lectionary, or initially as a marginal note.

MMR state: "The authors refuse to believe that the vast majority of copyists did their work with either a well-meant or subversive intent to alter the text of Scripture."  (p. 23)  We agree with this statement, because it is much more likely that the doxology was added from a well-meant intent to preserve the text of Scripture.  For the scribes in the Byzantine tradition from A.D. 1100 onward (the scribes who produced the vast majority of the extant copies), it is not necessary to speculate anything about their sincerity.  It seems likely that they had at least some exemplars that included the doxology, and it was also embedded in their liturgical tradition.  So, it would be unsurprising if they produced their copies blissfully unaware of the textual variant issue.

When it comes to analyzing the "internal evidence," MMR skip over the grammatical considerations of the text itself, which should be the usual starting place.  It's worth pointing out that kingdom, power, and glory fit Matthew's vocabulary.  The word, "Amen," is found in Matthew, though usually with a different significance.  The expression, "glory for ever, amen," seems more closely aligned the usage of the apostles and other New Testament authors in their epistles.  For example:

Jude 25 To the only wise God our Saviour, be glory and majesty, dominion and power, both now and ever. Amen.

1 Peter 5:11 To him be glory and dominion for ever and ever. Amen

Revelation 1:6 And hath made us kings and priests unto God and his Father; to him be glory and dominion for ever and ever. Amen.

Hebrews 13:21 Make you perfect in every good work to do his will, working in you that which is wellpleasing in his sight, through Jesus Christ; to whom be glory for ever and ever. Amen.

Phillippians 4:20 Now unto God and our Father be glory for ever and ever. Amen.

Perhaps because the immediate grammatical context does not provide a strong indication one way or another (though the use of "glory for ever, amen," is not typical of the gospels), MMR turns to three other texts of Scripture: Luke 11:2-4, 1 Chronicles 29:11, and 2 Timothy 4:18.

Regarding Luke 11:2-4, MMR acknowledge that the text in Luke is different from that in Matthew, but argue that this "proves nothing other than the fact that Jesus taught His disciples how top pray on more than one occasion."  Once again, MMR seem to be overlooking a few things.

First, even if the event were the same, it is not necessary for the gospel authors to provide the same account in both places.

Second, MMR seem to be unaware of the multiple places where the TR reading at Luke appears to reflect interpolation from Matthew.  Papyrus 75 and B have shorter readings, for example, omitting material that would harmonize Luke and Matthew. 

Third, MMR casts the question in an odd way: "Thus, this is not a compelling reason why the text of Luke 11:2-4 should be used to modify the text of Matthew 6:13." No one, I hope, is suggesting that Luke should be used to modify Matthew.  Rather, the absence of the doxology from Luke is simply evidence suggestive of the non-originality of the doxology in Matthew's possibly parallel account.

Regarding, 1 Chronicles 29:11, MMR state: "Some critics have suggested that this prayer of David is the source of the alleged 'added' doxology, but this assumes that at least one ancient copyist thought it appropriate to modify the exemplar before him by adding material."  I'm not sure of which critic MMR are referring to, and they don't bother to cite a source.  

There are multiple possibilities for where the first scribe to include this material may have got it, and multiple possibilities for how it was included in the text.  Other places where there is a similar doxology are the apostolic concluding greetings I mentioned above.  Daniel 2:37 provides an example of a similar blessing, though not directed to God in that instance. 

As I mentioned above, the most natural guess is that it was introduced as a marginal note or a scribe writing the Lord's prayer from memory, remembering the familiar liturgical doxology.

I should point out that whatever the source, the familiarity of a liturgical form of the Lord's prayer to most scribes is something that could be expected to provided a repeated influence on the text.  For example, various ancient translations provide a different ending than that found in the TR. 

Regarding 2 Timothy 4:18, MMR speculate that this is an allusion to the Lord's prayer as it is found in Matthew, because of the use of "evil," "kingdom," "glory," "for ever," and "amen."  While this text could hint at a familiarity with the Lord's prayer in the form found in Matthew in the TR, we don't have any reason to suppose that Paul knew Matthew's gospel.   The gospel alluded to by Paul in 1 Timothy 5:18, for example is Luke, specifically Luke 10:7.  Moreover, Luke was one of Paul's companions.  So, if there is a form of the Lord's prayer that would be most familiar to Paul, one might expect Luke's form, rather than Matthew's form.

Furthermore, the doxologies of Paul and other New Testament writers informed the usage of doxologies by the churches in the patristic period preceding Chrysostom.  Thus, it is reasonable to suppose that the doxology is formed from Paul, rather than vice versa.

Turning to "thematic considerations," which is another category of the intrinsic evidence, MMR provide the argument that inclusion of "glory" in the Lord's prayer would provide a bookend to the warning against seeking the glory of men in Matthew 6:2.  This argument is probably one of the strongest arguments they offer, particularly if we expand it to also include "Father in heaven".

6 Take heed that ye do not your alms before men, to be seen of them: otherwise ye have no reward of your Father which is in heaven. Therefore when thou doest thine alms, do not sound a trumpet before thee, as the hypocrites do in the synagogues and in the streets, that they may have glory of men. Verily I say unto you, They have their reward.  But when thou doest alms, let not thy left hand know what thy right hand doeth: That thine alms may be in secret: and thy Father which seeth in secret himself shall reward thee openly. And when thou prayest, thou shalt not be as the hypocrites are: for they love to pray standing in the synagogues and in the corners of the streets, that they may be seen of men. Verily I say unto you, They have their reward. But thou, when thou prayest, enter into thy closet, and when thou hast shut thy door, pray to thy Father which is in secret; and thy Father which seeth in secret shall reward thee openly. But when ye pray, use not vain repetitions, as the heathen do: for they think that they shall be heard for their much speaking. Be not ye therefore like unto them: for your Father knoweth what things ye have need of, before ye ask him. 

After this manner therefore pray ye: Our Father which art in heaven, Hallowed be thy name. Thy kingdom come, Thy will be done in earth, as it is in heaven. Give us this day our daily bread. And forgive us our debts, as we forgive our debtors. And lead us not into temptation, but deliver us from evil: For thine is the kingdom, and the power, and the glory, for ever. Amen.

For if ye forgive men their trespasses, your heavenly Father will also forgive you: But if ye forgive not men their trespasses, neither will your Father forgive your trespasses. Moreover when ye fast, be not, as the hypocrites, of a sad countenance: for they disfigure their faces, that they may appear unto men to fast. Verily I say unto you, They have their reward. But thou, when thou fastest, anoint thine head, and wash thy face; That thou appear not unto men to fast, but unto thy Father which is in secret: and thy Father, which seeth in secret, shall reward thee openly. Lay not up for yourselves treasures upon earth, where moth and rust doth corrupt, and where thieves break through and steal: But lay up for yourselves treasures in heaven, where neither moth nor rust doth corrupt, and where thieves do not break through nor steal: For where your treasure is, there will your heart be also.

The problem with this argument, though, is that the immediately preceding them is "asking for things," and the immediately following argument is regarding forgiveness of sins.  The doxology tends to break that thematic flow, and the single reference to glory, while it would serve as a bookend, would break the comments about forgiveness of sins into a separate discussion, despite its excellent fit with "forgive us our debts, as we forgive our debtors."  

MMR also emphasize that if the Lord's Prayer does not include the doxology, it would begin with the Father and end with the Devil ("deliver us from [the] evil [one]").  It's interesting that they adopt that translation for the purpose of this rhetoric.  As they acknowledge, they grabbed this piece of rhetoric from Dean Burgon.  This rhetorical flourish has little real impact: what better place would there be in the prayer for a reference to the devil (if that is what it is), than at the exact opposite end of the prayer.  Moreover, how could they possibly object to this bookending, since they allege that the original of the Lord's Prayer in Luke starts and ends like that!  If that's unfitting, and if Luke is really that way, then they have an argument with Jesus and with the Holy Spirit, not with us.

So, thematic considerations don't favor inclusion.

Regarding Greek manuscripts, MMR don't seem to have a very accurate understanding of the current state of textual criticism.  Instead, they seem to be following criticisms provided by TR supporters before the discovery of the papyri.

MMR state: "The witnesses deemed most valuable in modern text criticism are two Greek uncials ... called Sinaiticus and Vaticanus." MMR acknowledge that these two witnesses omit the doxology, but argue that "Such a joint witness is dubious," because these manuscripts differ with one another over 5,000 times.  

The high level of differences is normally thought of as evidence that these are independent witnesses.  So, suggesting that the differences somehow undermine the value of these witnesses is rather bizarre.

Furthermore, of course, the papyri have become a highly valuable asset in modern textual criticism.  For example, in Luke, Papyrus 75 provides a third apparently independent witness to the early state of Luke's text of the Lord's prayer, and demonstrates that the TR version of Luke's Lord's Prayer has been harmonized to Mathew's, rather than the reverse.

There are papyri witnesses of Matthew, but my understanding is that they are all rather incomplete, and that none includes Matthew 6.  Papyrus 1 includes part of Matthew 1, Papyrus 19 includes part of Matthew 10-11, and so on.  The closest fragment I could find where there is a textual difference between the TR and the main text of the NA27 is P64 at Matthew 5:22, where the papyrus supports the reading of Sinaiticus and Vaticanus against the later witnesses, including Washingtonianus.

Washingtonianus (W) is an early manuscript, probably from the fourth or fifth centuries.

While the papyrus witnesses do not address this text, there are other Greek manuscripts, such as the family of minuscules usually designated "family 1," that support the testimony of Sinaiticus and Vaticanus.

MMR say that because of the presence in W, the doxology's authenticity cannot be immediately dismissed.  W is useful evidence.  For example, W helps to demonstrate that some of the interpolations in the TR in Luke's Lord's Prayer are later than W, and confirms the pattern of interpolation over time that I've mentioned above.  That said, it's not conclusive and it is generally thought to be a little newer (maybe by a century) than Sinaiticus and Vaticanus and consequently subject to some interpolations that they lack.

Turning to "other ancient witnesses," MMR appeal to the Didache.  They mention that the Didache was written well before Sinaiticus and Vaticanus.  While that is true, the form of the Didache we have is largely derived from the twelfth century manuscript, Codex Hieroslymitanus (we know the age because the scribe dated the completion to June 11, 1056).  

While that version of the Didache has a doxology in the Lord's Prayer, it does not have the TR's doxology: it lacks the word "kingdom."  Furthermore, it is not clear that the version of the Didache found in that codex represents the original form of the work.  The earliest manuscripts of the Didache don't include section 8, which contains the Lord's Prayer.  What remains of the earliest translations (Coptic and Ethiopian) do not include this section and one further early translation has apparently been lost.  Shawn White has a helpful discussion (link).  Moreover, in the book referenced at that post, Shawn White provides an interesting insight into the doxology (pp. 42-43 of his book on the Didache):

The insight is that a number of doxologies are present as liturgical punctuation.  If this insight is correct, it can explain the Didache's doxology (different from TR Matthew) not as being intended to represent the text of Matthew, but rather as a liturgical addition thereto.  

MMR next refer to the writings of John Chrysostom, whose text of Matthew included the doxology.  It's quite true that Chrysostom's text had the doxology.  His writings provide evidence of that.  On the other hand, it is equally clear that the texts of Jerome and Augustine did not.  In fact, aside from the author of the incomplete commentary on Matthew (a commentary long erroneously ascribed to Chrysostom), Chrysostom seems to stand largely alone in the patristic period as a church father accepting this text as Scripture.  

MMR refer to the Apostolic Constitutions and the Peshitta. The Peshitta has an even longer doxology than the TR, stating "for ever and ever" as opposed to just "for ever."  Presumably, MMR are willing to acknowledge this as a scribe (or translator) adding to the text, which should give them pause about their theory that devout people would never do so.  There also seems to be some reversal of the wording regarding God's will being done "as in heaven so on earth," rather than "on earth as it is in heaven," which we might chalk up to translational style. It also appears that the "amen," which is typically found in Peshitta editions today may not be the most original reading (link to critical Peshitta).

MMR are notably silent of the fact that the doxology is absent from the Vulgate.  Thus,  when they say "the doxology was known to and used by Christians from the earliest of times," (p. 26) they are excluding most of the Western church.  Thus, Wycliffe's Matthew states: "and lead us not into temptation, but deliver us from evil. Amen." (Wycliffe translated from the Vulgate of his day, and died 1384)  Likewise, Aelfric's Homily on the Lord's Supper (in Anglo Saxon) does not include the doxology (link).  Aelfric was an English abbot who died around 1010.  So, it's not quite as though the English-speaking Christians have been using this from the earliest days.    

Next, MMR comment on liturgical use.  MMR note that the doxology was not part of the responsive reading in the liturgy known as Chrysostom's; it was recited by the priest alone.  MMR fail to recognize that this may be because it is not actually part of the prayer, and instead suggest that this liturgical division "seems eventually to have evolved into a formal textual separation, as can be clearly observed in the Bible versions and liturgies of the Roman Catholic Church today."  It's hard to understand this explanation.  They claim this would have been the effect on "congregants" who were "never asked or allowed to recite the doxology."  It's absolutely baffling how the a Greek liturgy used in Greek churches would have any influence at all in the West on Western "congregants," much less on Western scribes and translators.  Moreover, in fact, the places that used the liturgy of Chrysostom are exactly the places that have the doxology in the text.

MMR claim that omission of the doxology from the Lord's Prayer was "a decidedly Roman Catholic distinctive." (p. 27)  On the contrary, though, the non-insertion of the doxology goes back far before a distinctively Roman Catholic church, back at least to the days of Augustine and Jerome.  Moreover, there is no meaningful association between the ancient Greek manuscripts that do not insert the Lord's Prayer and the Roman Catholic church.  The fact that one is named for the Vatican is because it was held in a library there for a long time.

MMR acknowledge that both the Vulgate and a number of very old Latin manuscripts omit the Lord's Prayer.  They mention Calvin, who observes with surprise that the clause is omitted by "the Latins."

MMR claim that "Including the doxology of the Lord's Prayer was a Protestant distinctive," (p. 28) but fail to acknowledge that this is only because the Protestants of that era believed that the Lord's prayer was in the original Greek, a question answered for them and us by textual criticism, not adherence to human tradition.  Moreover, of course, Roman Catholic priest Erasmus was the one who included it in the first published Greek text.

I skip over the section on "Reformation Era" church history, in which they comment on the Complutensian Polyglot, Tyndale's first English translation, and his subsequent revision, except to comment on one point.  They say, "We find no Protestant challenging it until the nineteenth century." (p. 29)

On the other hand, the Protestant Johann Jakob Griesbach challenged it in the 1770's (link):

I suppose the reason that MMR were unfamiliar with this work is that they have had a rather brief exposure to the topic of textual criticism, since Griesbach is one of the big names in textual criticism. 

MMR, in the section titled "Textual Reconstruction," go on to suggest that it was Westcott and Hort to which we owe the idea of considering the readings of Sinaiticus and Vaticanus of high value.  Of course, they were valued before then, and it is not Westcott and Hort that brought them to prominence.  They quote something from Hort that describes the Textus Receptus as "vile" because it leans "entirely on late MSS."  

Westscott and Hort's first Green New Testament was published over 100 years after Griesbach's first. MMR call their work a project of "overthrowing the Protestant New Testament," which puts the least charitable spin on the efforts to restore the original text.

Finally, in the section about "Tomorrow's Text," MMR suggest that the coherence-based genealogical method (CBGM) may pose a challenge to the "text critical canons developed by Dr. Hort ...." (p. 30 - oddly, at p. 29 Hort is "Mr. Hort," and on p. 30 he is "Dr. Hort")  Of course, Hort didn't "develop" modern textual criticism, and the CBGM likewise doesn't challenge the principles of textual criticism: it just provides a more powerful tool.

MMR state: "the CBGM does seem to offer some hope concerning its potential re-inclusion." (pp. 30-31) I guess anyone can hope, but it would be very surprising indeed, given the weight of the evidence against originality, if the ECM were to adopt the doxology as original.  The absence from family 1 and the earliest uncials is hard to overcome.

MMR's conclusion accordingly fails, when they state: "As for the church, we have a much better confidence, knowing the doxology was known to-- and used by--- Christians from the earliest era of ecclesiastical history. Let all Christians therefore receive it as God's Word without qualification or mental reservation, and safeguard its place in our churches' standards." (p. 31) All this from the mere hope that textual criticism in the future may justify the text that has become traditional!

The video is not simply a regurgitation of the article.  MMR begin with introductions (about the first five minutes), and I will be quick to acknowledge that the OPC ministers have outstanding credentials as pastors, not to slight Pastor Riddle (the one Baptist) by any means.

One interesting point that the video emphasizes early on, but which has less emphasis (I think) in the article, is that the Westminster Standards adopt the doxology as part of the Lord's Prayer.  They do not explicitly say in the catechisms that this doxology is found in one place in the Bible, but they do teach the Lord's prayer as including this doxology.

Of course, the doxology is itself perfectly orthodox, so it should not cause any consternation.  Riddle states (about 10 minutes in) that if the doxology is not original to the Lord's Prayer then the catechism would be teaching adherence to "something unbiblical."  One wonders what Riddle thinks of the Heidelberg Catechism going through the Apostles' Creed! Does he find that to be "something unbiblical" as well?

In the video, regarding the Didache, there is this exchange (around 21 minutes):

Riddle: You guys point out in your article that there is some early evidence- quite early evidence in fact - for the doxology of the Lord's Prayer that shows its antiquity. It certainly wasn't something invented in, you know, the fifth century or something like that, so Christian, what are some of the other ancient witnesses to the authenticity of the doxology?

McShaffrey: Well, the earliest witness is a document called the Didache, which I think most conservative evangelicals would date to the first century.  And it contains the doxology at the end of the Lord's Prayer, and it even commands the reader to pray this three times a day and of course it was a document for discipleship of the early Christians. So, if oldest is best is really our law in text critical matters we have a witness predating the Sinai and Vatican manuscripts by a few hundred years, and I think it's an early, valid and probably catholic witness everybody has heard of the Didache and naybe even made use of it.

Riddle: Right

McShaffrey: But I know the modern critics - you know - say that's not a Greek manuscript of the New Testament text so it doesn't count.

Riddle: Yeah

Some necessary corrections:

1) I don't think enough "conservative evangelicals" know about the Didache to have any kind of educated guess as to its date of composition.  The "two ways" material from the beginning of the Didache is probably the oldest material in the work.  Moreover, there is a lot of speculation regarding how and when the Didache (in the form its usually found today) was composed.  

2) The Didache has a doxology after the Lord's prayer, but the doxology differs from the TR's doxology.  Moreover, as noted above, the Didache has doxology material elsewhere, which provides an indication that there may not be any intent to suggest that either Matthew's or Luke's Lord's Prayer had a doxology.  

3) In terms of manuscripts witnesses, the only essentially complete manuscript of the Didache is an 11th century manuscript.  Moreover, that is literally the only manuscript of the Didache that has the Lord's prayer.  So, to suggest that the Didache is an earlier witness to the Lord's prayer is misleading at best.

4) In terms of catholicity, note that although the work probably had some influence at one time, only one substantially complete manuscript survives.  So, the idea that it received some kind of widespread and universal reception does not seem sound.

5) As to the orthodoxy of the writers, there is an odd command to fast on Wednesday and Friday, rather than on Tuesday and Thursday.  Likewise, the discussion of the Lord's Supper does not appear to have any reference to Christ's death, which is certainly odd. Similarly the group that prepared this work seems to have had a regular office of prophet, with regulations on the office.  Finally, while faith is mentioned a few times, its salvific role seems to be only as an aid to good works (see Didache 16). To describe this as the catholic faith is a stretch.

6) Modern textual critics do not necessarily ignore witnesses other than the Greek manuscripts.  While those of us, like myself, who hold to the preservation of the text will not accept a reading that is not found in the Greek manuscripts, there is still value in ancient quotations from Scripture in establishing which reading is original.

I appreciate that Riddle brings up (around 23:30) the issue that the Didache's doxology does not match that of the TR.  His insistence that it is a reference to the doxology is misplaced, however.  For example, this same doxology is found in the Prayer after Communion (Didache 10), and a similar one is found in the Eucharist prayer (Didache 9).  Moreover, the Didache is not only difference because of the word "kingdom," but also because it lacks the "Amen."  

As an aside, I think it should fascinate my Roman Catholic readers to note that the author(s) of the Didache focus on the bread metaphorically in a way similar to what Augustine eventually did: "Even as this broken bread was scattered over the hills, and was gathered together and became one, so let Your Church be gathered together from the ends of the earth into Your kingdom; for Yours is the glory and the power through Jesus Christ forever."  After all, bread comes from grain and represents the Body of Christ, which is the Church.

Around 25 minutes in, Riddle comes to the same inference that I did, in reading the article, namely that it seems McShaffrey and Mahlen are suggesting that the manuscripts that lack the doxology arose due to liturgical influence.

Mahlen seems to acknowledge the point I raised above, namely that the non-recitation seems to support the idea that it was not actually part of Matthew's (or Luke's) Lord's Prayer. However, Riddle seems to urge the point set forth in the article, namely that a couple of hundred years of liturgical practice of not having the people say the doxology could lead to a scribal omission.

The challenge with the article's and Riddle's point is that there is not compelling evidence that liturgical practice of what is commonly called "The Divine Liturgy of Chrysostom," is much more ancient than Chrysostom himself, such that it would explain multiple seemingly independent scribal omissions in Sinaiticus and Vaticanus.

The video next turns to the doxology as a "distinctly Protestant reading," though obviously it is more accurately described as a distinctively Eastern Orthodox reading that was brought into Protestant Bibles by its prevalence especially in the later Greek manuscripts.

It's amusing to hear Pastor McShaffrey (I think it was him) speak of the "papish Polyglot," which omitted the doxology, in contrast to the work of Erasmus (with no acknowledgment that his first printing was literally dedicated to the pope).  Thankfully, Riddle points out a few minutes later that Erasmus was a Roman Catholic. 

I appreciate Riddle's acknowledgment that Tyndale's first edition did not include it.  I also agree with and appreciate Riddle's acknowledgment that the doxology is very unlikely to be found to be original by the ECM.  

Thankfully, Matthew is the very next book to which CBGM is to be applied, so we should not have to wait long to see.

I also appreciate the admission by Pastors Mahlen and McShaffrey that their article was intended to influence debate within the OPC on the subject.  I also appreciate their acknowledgment that their presbytery did not accept their motion to overture the General Assembly on the subject.

I would exhort Pastors Mahlen and McShaffrey to read more on the subject, as I think they could benefit from a more detailed understanding of the subject they have chosen to discuss/debate publicly. 

Post Script:

On the topic of "scribes would never," I think Pastors Mahlen and McShaffrey should familiarize themselves with the manuscripts a bit more.  Taking Matthew 6:13 as an example, manuscript 38 adds "των αιωνων" to make it "forever and ever," manuscript 157 adds "του π̅ρ̅ς̅ και του υιου και του αγιου π̅ν̅ς̅ " before "forever," while manuscript 740 adds "ου π̅ρ̅ς̅ και του υιου και του αγιου π̅ν̅ς̅ νυν και αει και" at that same point.  These longer examples of the doxological form are even more Trinitarian than the TR.  Yet is the longest doxology original?  No.    

Update of August 23, 2022:

Dan Chapa asked "Regarding the Didache, 1) do you have any textual variants of the Didache that exclude the doxology and 2) if you hypothesize that it's a later insertion, why doesn't it match most Greek manuscripts?"

As to (1), textual variants can only occur when you have at least two copies of something.  As the article above explains, there is only one manuscript of the Didache (in any language) that has this section.  It would be interesting to check, and perhaps I will be able to do so later, whether the same and similar doxologies found in other places in the Didache have any textual variants.  A Coptic manuscript, for example, includes at least a portion of Didache 10:3 and following, which could at least confirm whether the doxology used at 10:6 is as ancient as the Coptic version.  Evidently, the Coptic/Sahidic doxology to the Lord's Prayer likewise lacks the reference to "kingdom," though it includes an "amen."  I think (based on reading Niederwimmer's commentary on that point, see p. 161, which does not mention a textual variant) that the form "the power and the glory" is present in the Coptic ms. of 10:6.  Unfortunately for us, the Coptic does not include 8.  The Georgian version, which seems to have been lost (since the 1930s), apparently had 8 (and apparently had "sixth day" instead of the literal Greek "preparation day" both of which mean Friday).  There does seem to be a difference at 10:6 (Herr ist gekommen und sein Reich für immer zu uns - which, if I've correctly understood the collator means that the Georgian text does not mention power and glory there).  I think Shawn White mentioned that he didn't address the now-lost Georgian version or its collation by Dr. Gregor Peradse because it is unclear whether or not the Georgian version is just a modern translation. Dr. Peradse provides some consideration of the date based on the Georgian spellings used, which suggests that the manuscript he saw was not particularly ancient, but that it (or its exemplar) may have been medieval.  In any event, that's the closest we can come to finding a textual variant here.

As to (2), I assume you are talking about the speculation I made elsewhere that a Greek scribe could have harmonized the text of the prayer to align with his memory of the Lord's Prayer.  This speculative path does seem less likely, given that the doxology provided in the Greek manuscript is not the doxology used in the Greek liturgy nor that found in late Greek manuscripts.  Instead, the doxology seems at first blush to come from a tradition like the Coptic tradition, which omits "kingdom."  That could be original to the composition of this section of the Didache (whenever that was) or it could be a later insertion to this section.  The fact that the identical doxology used in 10:6 and a very similar one is used in 9 (neither of which is a quotation from Scripture) suggests that this is simply the author's liturgical addition, like the instruction that the prayer be prayed thrice daily.