Genesis 17:20

17 Then Abraham fell upon his face, and laughed, and said in his heart, Shall [a child] be born to him that is a hundred years old? and shall Sarah, who is ninety years old, bear?

18 And Abraham said to God, O that Ishmael might live before thee!

19 And God said, Sarah thy wife shall bear thee a son indeed; and thou shalt call his name Isaac: and I will establish my covenant with him for an everlasting covenant, [and] with his seed after him.

20 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.

21 But my covenant will I establish with Isaac, whom Sarah shall bear to thee at this set time in the next year.

22 And he ceased talking with him, and God went up from Abraham.

23 And Abraham took Ishmael his son, and all that were born in his house, and all that were bought with his money, every male among the men of Abraham's house; and circumcised the flesh of their foreskin, in the same day, as God had said to him.