Genesis 17:17-24

17Immediately, Abraham bowed with his face touching the ground. He laughed as he thought to himself, “Can a son be born to a hundred-year-old man? Can Sarah, a ninety-year-old woman, have a child?”

18Then Abraham said to God, “Why not let Ishmael be my heir?”

19God replied, “No! Your wife Sarah will give you a son, and you will name him Isaac [He Laughs]. I will make an everlasting promise to him and his descendants.

20I have heard your request about Ishmael. Yes, I will bless him, make him fertile, and increase the number of his descendants. He will be the father of 12 princes, and I will make him a great nation.

21But I will make my promise to Isaac. Sarah will give birth to him at this time next year.”

22When God finished speaking with Abraham, he left him.

23So Abraham took his son Ishmael, everyone born in his household, and everyone bought with money—every male in his household—and circumcised them that day, as God had told him.

24Abraham was 99 years old when he was circumcised.