Genesis 17:22-27

22And he left off talking with him; and 1God went up from Abraham. 23And Abraham took Ishmael his son, and all who were born in his house, and all who were bought with his money — every male among the people of Abraham's house — and circumcised the flesh of their foreskin on that same day, as 2God had said to him. 24And Abraham was ninety-nine years old when he was circumcised in the flesh of his foreskin. 25And Ishmael his son was thirteen years old when he was circumcised in the flesh of his foreskin. 26In the selfsame day was Abraham circumcised, and Ishmael his son; 27and all the men of his house, born in his house, or bought with money of the stranger, were circumcised with him.