Genesis 17:10-14

17:10 This is my requirement that you and your descendants after you must keep: Every male among you must be circumcised. 17:11 You must circumcise the flesh of your foreskins. This will be a reminder of the covenant between me and you. 17:12 Throughout your generations every male among you who is eight days old must be circumcised, whether born in your house or bought with money from any foreigner who is not one of your descendants. 17:13 They must indeed be circumcised, whether born in your house or bought with money. The sign of my covenant will be visible in your flesh as a permanent reminder. 17:14 Any uncircumcised male who has not been circumcised in the flesh of his foreskin will be cut off from his people – he has failed to carry out my requirement.”

Leviticus 12:3

12:3 On the eighth day the flesh of his foreskin must be circumcised.

Romans 4:9-11

4:9 Is this blessedness then for the circumcision or also for the uncircumcision? For we say, “faith was credited to Abraham as righteousness.” 4:10 How then was it credited to him? Was he circumcised at the time, or not? No, he was not circumcised but uncircumcised! 4:11 And he received the sign of circumcision as a seal of the righteousness that he had by faith while he was still uncircumcised, so that he would become the father of all those who believe but have never been circumcised, that they too could have righteousness credited to them.

Galatians 3:17

3:17 What I am saying is this: The law that came four hundred thirty years later does not cancel a covenant previously ratified by God, so as to invalidate the promise.