Genesis 17:10-12

Amplified Bible

¹⁰ This is [the sign of] My covenant, which you shall keep and faithfully obey, between Me and you and your descendants after you: Every male among you shall be circumcised. ¹¹ And you shall be circumcised in the flesh of your foreskins, and it shall be the sign (symbol, memorial) of the covenant between Me and you. ¹² Every male among you who is eight days old shall be circumcised throughout your generations, [including] a servant whether born in the house or one who is purchased with [your] money from any foreigner, who is not of your descendants.