'Circumcision' in the Bible

And God gave Abraham a covenant [a formal agreement to be strictly observed] of [which] circumcision [was the sign]; and so [under these circumstances] Abraham became the father of Isaac, and circumcised him on the eighth day; and Isaac [became the father] of Jacob, and Jacob [became the father] of the twelve patriarchs.

So when Peter went up to Jerusalem, those of the circumcision [certain Jewish believers who followed the Law] took issue with him [for violating Jewish customs],