Genesis 17:11
And you shall circumcise the flesh of your foreskin; and it shall be a token of the covenant between me and you.
Nave's Topical Index—AKJV

Romans 4:11
And he received the sign of circumcision, a seal of the righteousness of the faith which he had yet being uncircumcised: that he might be the father of all them that believe, though they be not circumcised; that righteousness might be imputed to them also:
Nave's Topical Index—AKJV