Genesis 17:23

20 As to Ishmael, I have heard thee; lo, I have blessed him, and made him fruitful, and multiplied him, very exceedingly; twelve princes doth he beget, and I have made him become a great nation;

21 and My covenant I establish with Isaac, whom Sarah doth bear to thee at this appointed time in the next year;`

22 and He finisheth speaking with him, and God goeth up from Abraham.

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;

26 in this self-same day hath Abraham been circumcised, and Ishmael his son;