Genesis 17:25

²³  And Abraham took Ishmael his son, and all that were born in his house, and all that were bought with his money, every male among the men of Abraham's house; and circumcised the flesh of their foreskin in the selfsame day, as God had said unto him.

²⁴  And Abraham was ninety years old and nine, 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.

²⁶  In the selfsame day was Abraham circumcised, and Ishmael his son.

²⁷  And all the men of his house, born in the house, and bought with money of the stranger, were circumcised with him.