Genesis 17:17-24

17Then Abraham 1fell on his face and laughed, and said in his heart, “Will a child be born to a man a hundred years old? And 2will Sarah, who is ninety years old, give birth to a child?” 18And Abraham said to God, “Oh that Ishmael might live before You!” 19But God said, “No, but your wife Sarah will bear you 3a son, and you shall name him 4Isaac; and 5I will establish My covenant with him as an everlasting covenant for his 6descendants after him. 20As for Ishmael, I have heard you; behold, I will bless him, and 7make him fruitful and multiply him exceedingly. 8He shall father twelve princes, and I will make him into a 9great nation. 21But I will establish My covenant with 10Isaac, whom 11Sarah will bear to you at this season next year.” 22When He finished talking with him, 12God went up from Abraham.

23Then Abraham took his son Ishmael, and all the slaves who were 13born in his house and all who were bought with his money, every male among the men of Abraham’s household, and circumcised the flesh of their foreskin on this very same day, 14as God had said to him. 24Now Abraham was ninety-nine years old when 15he was circumcised in the flesh of his foreskin.