Genesis 17:23-27

Then Abraham took his son Ishmael and all his servants, whether houseborn or purchased—every male in his household—and circumcised them, cutting off their foreskins that very day, just as God had told him. Abraham was ninety-nine years old when he was circumcised. His son Ishmael was thirteen years old when he was circumcised. Abraham and Ishmael were circumcised the same day together with all the servants of his household, those born there and those purchased from outsiders—all were circumcised with him. * * *