Genesis 17:9-14

9God also said to Abraham, “You and your descendants in generations to come are to be faithful to my promise.

10This is how you are to be faithful to my promise: Every male among you is to be circumcised.

11All of you must be circumcised. That will be the sign of the promise from me to you.

12For generations to come every male child who is eight days old must be circumcised, whether he is born in your household or bought with money from a foreigner who’s not related to you.

13Every male born in your household or bought with your money is to be circumcised without exception. So my promise will be a sign on your flesh, an everlasting promise.

14Any uncircumcised male must be excluded from his people because he has rejected my promise.”