Genesis 17:11-14

BBE(i) 11 In the flesh of your private parts you are to undergo it, as a mark of the agreement between me and you. 12 Every male among you, from one generation to another, is to undergo circumcision when he is eight days old, with every servant whose birth takes place in your house, or for whom you gave money to someone of another country, and not of your seed. 13 He who comes to birth in your house and he who is made yours for a price, all are to undergo circumcision; so that my agreement may be marked in your flesh, an agreement for all time. 14 And any male who does not undergo circumcision will be cut off from his people: my agreement has been broken by him.