Genesis 17:7-13

7And I will establish My covenant between Me and you and your descendants after you in their generations, for an everlasting covenant, to be God to you and your descendants after you.

8Also I give to you and your descendants after you the land in which you are a stranger, all the land of Canaan, as an everlasting possession; and I will be their God.”

9And God said to Abraham: “As for you, you shall keep My covenant, you and your descendants after you throughout their generations.

10This is My covenant which you shall keep, between Me and you and your descendants after you: Every male child among you shall be circumcised;

11and you shall be circumcised in the flesh of your foreskins, and it shall be a sign of the covenant between Me and you.

12He who is eight days old among you shall be circumcised, every male child in your generations, he who is born in your house or bought with money from any foreigner who is not your descendant.

13He who is born in your house and he who is bought with your money must be circumcised, and My covenant shall be in your flesh for an everlasting covenant.