Circumcision: Institution of

This is My covenant with you and your descendants after you, which you are to keep: Every male among you must be circumcised. …

And on the eighth day the flesh of the boy’s foreskin is to be circumcised.

But because Moses gave you circumcision, you circumcise a boy on the Sabbath (not that it is from Moses, but from the patriarchs.)

Then God gave Abraham the covenant of circumcision, and Abraham became the father of Isaac and circumcised him on the eighth day. And Isaac became the father of Jacob, and Jacob of the twelve patriarchs.

And he received the sign of circumcision as a seal of the righteousness that he had by faith while he was still uncircumcised. So then, he is the father of all who believe but are not circumcised, in order that righteousness might be credited to them.