Genesis 17:10

7 `And I have established My covenant between Me and thee, and thy seed after thee, to their generations, for a covenant age-during, to become God to thee, and to thy seed after thee;

8 and I have given to thee, and to thy seed after thee, the land of thy sojournings, the whole land of Canaan, for a possession age-during, and I have become their God.`

9 And God saith unto Abraham, `And thou dost keep My covenant, thou and thy seed after thee, to their generations;

10 this [is] My covenant which ye keep between Me and you, and thy seed after thee: Every male of you [is] to be circumcised;

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;