Genesis 17:13

10 This [is] my covenant, which ye shall keep between me and you, and thy seed after thee; Every male-child among you shall be circumcised.

11 And ye shall circumcise the flesh of your foreskin; and it shall be a token of the covenant betwixt me and you.

12 And he that is eight days old shall be circumcised among you, every male-child in your generations, he that is born in the house, or bought with money of any stranger, who [is] not of thy seed.

13 He that is born in thy house, and he that is bought with thy money, must needs be circumcised: and my covenant shall be in your flesh for an everlasting covenant.

14 And the uncircumcised male-child, whose flesh of his foreskin is not circumcised, that soul shall be cut off from his people; he hath broken my covenant.

15 And God said to Abraham, As for Sarai thy wife, thou shalt not call her name Sarai, but Sarah [shall] her name [be].

16 And I will bless her, and give thee a son also by her: yea, I will bless her, and she shall be [a mother] of nations; kings of people shall proceed from her.