Galatians 2:7

2:7 On the contrary, when they saw that I was entrusted with the gospel to the uncircumcised just as Peter was to the circumcised

Galatians 5:2-3

5:2 Listen! I, Paul, tell you that if you let yourselves be circumcised, Christ will be of no benefit to you at all! 5:3 And I testify again to every man who lets himself be circumcised that he is obligated to obey the whole law.