Genesis 17:26

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.