23On that very day Abraham took his son Ishmael and all those born in his household or purchased with his money — every male among the members of Abraham’s household — and he circumcised them, just as God had told him.
24So Abraham was ninety-nine years old when he was circumcised,
25and his son Ishmael was thirteen;
26Abraham and his son Ishmael were circumcised on the same day.
27And all the men of Abraham’s household — both servants born in his household and those purchased from foreigners — were circumcised with him.
— Genesis 17:23-27