Genesis 17:23-25

English Standard Version

²³ Then Abraham took Ishmael his son and all those born in his house or bought with his money, every male among the men of Abraham's house, and he circumcised the flesh of their foreskins that very day, as God had said to him. ²⁴ Abraham was ninety-nine years old when he was circumcised in the flesh of his foreskin. ²⁵ And Ishmael his son was thirteen years old when he was circumcised in the flesh of his foreskin.