Genesis 17:10-12

New Revised Standard Version, Anglicised

¹⁰ This is my covenant, which you shall keep, between me and you and your offspring after you: Every male among you shall be circumcised. ¹¹ You shall circumcise the flesh of your foreskins, and it shall be a sign of the covenant between me and you. ¹² Throughout your generations every male among you shall be circumcised when he is eight days old, including the slave born in your house and the one bought with your money from any foreigner who is not of your offspring.