Genesis 17:20And later to Hagar:
And as for Ishmael, I have heard thee: Behold, I have blessed him, and will make him fruitful, and will multiply him exceedingly; twelve princes shall he beget, and I will make him a great nation.
Genesis 21:18Zakir argued that what makes a nation great is monotheism or specifically worshiping the one true God, and that consequently the Arabian conversion to Islam is the fulfillment of this prophecy, since prior to that time the Arabs were mostly polytheists. He seemed to appeal to this passage as though it defines greatness as he has argued:
Arise, lift up the lad, and hold him in thine hand; for I will make him a great nation.
Deuteronomy 4:6-8But that passage is not defining what makes a nation great, it was what makes a great nation wise. It is comparing Israel to the great nations.
Keep therefore and do them; for this is your wisdom and your understanding in the sight of the nations, which shall hear all these statutes, and say, Surely this great nation is a wise and understanding people. For what nation is there so great, who hath God so nigh unto them, as the LORD our God is in all things that we call upon him for? And what nation is there so great, that hath statutes and judgments so righteous as all this law, which I set before you this day?
In the Scriptures, the term "great nation" refers to any large, populous, and/or mighty nation. For example:
Deuteronomy 4:38In short, it is not necessary for the prophecy that the nation be a monotheist or YHWH-worshiping in order to be considered "great." That is because while in English these days the term "great" can mean "wonderful," the primary significance of the Hebrew word it is translating is one of large size, power, or importance (which used to be the primary meaning of the English word, "great," as well). A great nation is not necessarily one that is morally praiseworthy.
To drive out nations from before thee greater and mightier than thou art, to bring thee in, to give thee their land for an inheritance, as it is this day.
When the LORD thy God shall bring thee into the land whither thou goest to possess it, and hath cast out many nations before thee, the Hittites, and the Girgashites, and the Amorites, and the Canaanites, and the Perizzites, and the Hivites, and the Jebusites, seven nations greater and mightier than thou;
Hear, O Israel: Thou art to pass over Jordan this day, to go in to possess nations greater and mightier than thyself, cities great and fenced up to heaven,
Then will the LORD drive out all these nations from before you, and ye shall possess greater nations and mightier than yourselves.
For the LORD hath driven out from before you great nations and strong: but as for you, no man hath been able to stand before you unto this day.
Who smote great nations, and slew mighty kings;
For, lo, I will raise and cause to come up against Babylon an assembly of great nations from the north country: and they shall set themselves in array against her; from thence she shall be taken: their arrows shall be as of a mighty expert man; none shall return in vain.
All this argues against the major premise of Mr. Hussain's argument. The minor argument is also in dispute, since Islam does not worship YHWH, nor does it have laws that are as righteous as those of Old Testament Israel. However, even if we assumed that the minor premise were correct, the major premise fails as discussed above. Accordingly, in this post I haven't provided a detailed argument about the minor premise.
Thus, as to the first prophecy, we have no reason to see Mohammed prophesied particularly in the Old Testament. The Ishmaelites were a great nation before Mohammed was born. For example, the Ishmaelites included the Midianites:
Judges 8:22-24Moreover, the prophecy regarding Ishmael was fulfilled in his own lifetime:
Then the men of Israel said unto Gideon, Rule thou over us, both thou, and thy son, and thy son's son also: for thou hast delivered us from the hand of Midian. And Gideon said unto them, I will not rule over you, neither shall my son rule over you: the Lord shall rule over you. And Gideon said unto them, I would desire a request of you, that ye would give me every man the earrings of his prey. (For they had golden earrings, because they were Ishmaelites.)
Genesis 25:12-18So, we know exactly who the twelve princes were, by name. Thus, there is no need to look for Mohammed as a fulfillment of this prophecy. There is a minor premise that is also in question, namely the question of whether the Arabians are actually the descendants of Ishmael. While I don't have any particular reason to doubt their claim, I'm unaware of any genealogy that actually demonstrates the connection.
Now these are the generations of Ishmael, Abraham's son, whom Hagar the Egyptian, Sarah's handmaid, bare unto Abraham: and these are the names of the sons of Ishmael, by their names, according to their generations: the firstborn of Ishmael, Nebajoth; and Kedar, and Adbeel, and Mibsam, and Mishma, and Dumah, and Massa, Hadar, and Tema, Jetur, Naphish, and Kedemah: these are the sons of Ishmael, and these are their names, by their towns, and by their castles; twelve princes according to their nations. And these are the years of the life of Ishmael, an hundred and thirty and seven years: and he gave up the ghost and died; and was gathered unto his people. And they dwelt from Havilah unto Shur, that is before Egypt, as thou goest toward Assyria: and he died in the presence of all his brethren.
N.B. It should go without saying, but this post should not be taken as in any way a criticism of Dr. White's response during the debate. I was able to spend an unlimited amount of time preparing my response, and I am not required to fit my responses to each of Mr. Hussain's arguments into a fixed amount of time or space. In a real debate, the debaters have to prioritize based on limited preparation time and limited response time.