Genesis 17
23 Ref Abraham took Ishmael his son, all who were born in his house, and all who were bought with his money; every male among the men of Abraham's house, and circumcised the flesh of their foreskin in the same day, as God had said to him.
24 Ref Abraham was ninety-nine years old, when he was circumcised in the flesh of his foreskin.
25 Ishmael, his son, was thirteen years old when he was circumcised in the flesh of his foreskin.
26 Ref In the same day both Abraham and Ishmael, his son, were circumcised.
27 Ref All the men of his house, those born in the house, and those bought with money of a foreigner, were circumcised with him.