Genesis 17:10-12

Young's Literal Translation

¹⁰ this [is] My covenant which ye keep between Me and you, and thy seed after thee: Every male of you [is] to be circumcised;

¹¹ and ye have circumcised the flesh of your foreskin, and it hath become a token of a covenant between Me and you.

¹² `And a son of eight days is circumcised by you; every male to your generations, born in the house, or bought with money from any son of a stranger, who is not of thy seed;