Genesis 17:10-13

Revised Standard Version

¹⁰ This is my covenant, which you shall keep, between me and you and your descendants after you: Every male among you shall be circumcised. ¹¹ You shall be circumcised in the flesh of your foreskins, and it shall be a sign of the covenant between me and you. ¹² He that is eight days old among you shall be circumcised; every male throughout your generations, whether born in your house, or bought with your money from any foreigner who is not of your offspring, ¹³ both he that is born in your house and he that is bought with your money, shall be circumcised. So shall my covenant be in your flesh an everlasting covenant.