Genesis 17:23–27

23 So Abraham took his son Ishmael and those born in his household or purchased—every male among the members of Abraham’s household—and he circumcised the flesh of their foreskin on that very day, just as God had said to him. 24 Abraham was ninety-nine years old when the flesh of his foreskin was circumcised, 25 and his son Ishmael was thirteen years old when the flesh of his foreskin was circumcised. 26 On that very day Abraham and his son Ishmael were circumcised. 27 And all the men of his household—whether born in his household or purchased from a foreigner—were circumcised with him.