sharp knife.

circumcise

Genesis 17:10-14
This is My covenant with you and your descendants after you, which you are to keep: Every male among you must be circumcised. . . .

Deuteronomy 10:16
Circumcise your hearts, therefore, and stiffen your necks no more.

Deuteronomy 30:6
The LORD your God will circumcise your hearts and the hearts of your descendants, and you will love Him with all your heart and all your soul, so that you may live.

Romans 2:29
No, a man is a Jew because he is one inwardly, and circumcision is a matter of the heart, by the Spirit, not by the written code. Such a man's praise does not come from men, but from God.

Romans 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 then, he is the father of all who believe but are not circumcised, in order that righteousness might be credited to them.

Colossians 2:11
In Him you were also circumcised in the putting off of your sinful nature, with the circumcision performed by Christ and not by human hands.