Genesis 17:23-25

Young's Literal Translation

²³ And Abraham taketh Ishmael his son, and all those born in his house, and all those bought with his money -- every male among the men of Abraham's house -- and circumciseth the flesh of their foreskin, in this self-same day, as God hath spoken with him.

²⁴ And Abraham [is] a son of ninety and nine years in the flesh of his foreskin being circumcised;

²⁵ and Ishmael his son [is] a son of thirteen years in the flesh of his foreskin being circumcised;