Genesis 17:17-24

17Then Abraham bowed down with his face to the ground and laughed as he said to himself, “Can a son be born to a man who is a hundred years old? Can Sarah bear a child at the age of ninety?”

18Abraham said to God, “O that Ishmael might live before you!”

19God said, “No, Sarah your wife is going to bear you a son, and you will name him Isaac. I will confirm my covenant with him as a perpetual covenant for his descendants after him.

20As for Ishmael, I have heard you. I will indeed bless him, make him fruitful, and give him a multitude of descendants. He will become the father of twelve princes; I will make him into a great nation.

21But I will establish my covenant with Isaac, whom Sarah will bear to you at this set time next year.”

22When he finished speaking with Abraham, God went up from him.

23Abraham took his son Ishmael and every male in his household (whether born in his house or bought with money) and circumcised them on that very same day, just as God had told him to do.

24Now Abraham was 99 years old when he was circumcised;