Genesis 17:7-13

7I will establish My covenant as an everlasting covenant between Me and you and your descendants after you, to be your God and the God of your descendants after you.

8And to you and your descendants I will give the land where you are residing—all the land of Canaan—as an eternal possession; and I will be their God.”

9God also said to Abraham, “You must keep My covenant—you and your descendants in the generations after you. 10This is My covenant with you and your descendants after you, which you are to keep: Every male among you must be circumcised. 11You are to circumcise the flesh of your foreskin, and this will be a sign of the covenant between Me and you.

12Generation after generation, every male must be circumcised when he is eight days old, including those born in your household and those purchased from a foreigner—even those who are not your offspring. 13Whether they are born in your household or purchased, they must be circumcised. My covenant in your flesh will be an everlasting covenant.