Genesis 17:14

11 and ye have circumcised the flesh of your foreskin, and it hath become a token of a covenant between Me and you.

12 `And a son of eight days is circumcised by you; every male to your generations, born in the house, or bought with money from any son of a stranger, who is not of thy seed;

13 he is certainly circumcised who [is] born in thine house, or bought with thy money; and My covenant hath become in your flesh a covenant age-during;

14 and an uncircumcised one, a male, the flesh of whose foreskin is not circumcised, even that person hath been cut off from his people; My covenant he hath broken.`

15 And God saith unto Abraham, `Sarai thy wife -- thou dost not call her name Sarai, for Sarah [is] her name;

16 and I have blessed her, and have also given to thee a son from her; and I have blessed her, and she hath become nations -- kings of peoples are from her.`

17 And Abraham falleth upon his face, and laugheth, and saith in his heart, `To the son of an hundred years is one born? or doth Sarah -- daughter of ninety years -- bear?`