Galatians 6:13-14

For even the circumcised [Jews] themselves do not [really] keep the Law, but they want to have you circumcised so that they may boast in your flesh [that is, in the fact that they convinced you to be circumcised]. But far be it from me to boast [in anything or anyone], except in the cross of our Lord Jesus Christ, through whom the world has been crucified to me, and I to the world.