Dialogue with Trypho 66He proves from Isaiah that God was born from a virgin.

And I, resuming the discourse where I had left off at a previous stage, when proving that He was born of a virgin, and that His birth of a virgin had been predicted by Isaiah, quoted again the same prophecy. It is as follows 'And the Lord spoke again to Ahaz, saying, Ask for thyself a sign from the Lord thy God, in the depth or in the height. And Ahaz said I will not ask, neither will I tempt the Lord. And Isaiah said, Hear then, O house of David; Is it no small thing for you to contend with men? And how do you contend with the Lord? Therefore the Lord Himself will give you a sign; Behold, the virgin shall conceive, and shall bear a son, and they shall call his name Immanuel. Butter and honey shall he eat; before he knows or prefers the evil he will choose out the good. For before the child knows ill or good, he rejects evil by choosing out the good. For before the child knows how to call father or mother, he shall receive the power of Damascus, and the spoil of Samaria, in presence of the king of Assyria. And the land shall be forsaken, which thou shalt with difficulty endure in consequence of the presence of its two kings. But God shall bring on thee, and on thy people, and on the house of thy father, days which have not yet come upon thee since the day in which Ephraim took away from Judah the king of Assyria.' " And I continued: "Now it is evident to all, that in the race of Abraham according to the flesh no one has been born of a virgin, or is said to have been born [of a virgin], save this our Christ."