Acts 11:2

And when Peter was come up to Jerusalem, they that were of the circumcision contended with him,

And when Peter was come up to Jerusalem - probably hastening his return there, in order to report the great revolution which God had worked in his views about the Gentiles, and to meet any difficulties which might be felt on the subject.

They that were of the circumcision - the circumcised believers; but here probably referring to the zealots for circumcision including, not improbably, apostles as well as others.