Mul (H4135) is the primary verb for circumcision. God commands Abraham to circumcise all males as the sign of the covenant (Genesis 17). Moses and Joshua both perform circumcisions at covenant-renewal moments. The prophets speak of the deeper circumcision of the heart.
Circumcision (mul) is the sign of covenant inclusion in Israel. But the OT itself points beyond the physical rite. Deuteronomy 10:16 commands 'circumcise the foreskin of your heart.' Jeremiah 4:4 echoes this. Paul's theology in Romans 2 and Colossians 2 draws directly on this prophetic thread — the true circumcision is a work of the Spirit that cuts away the flesh nature, fulfilled in union with Christ.