'Circumcision' in the Bible

He gave him the covenant of circumcision. So Abraham became the father of Isaac, and circumcised him the eighth day. Isaac became the father of Jacob, and Jacob became the father of the twelve patriarchs.

They of the circumcision who believed were amazed, as many as came with Peter, because the gift of the Holy Spirit was also poured out on the Gentiles.

When Peter had come up to Jerusalem, those who were of the circumcision contended with him,