But contrariwise, when they saw that the gospel of the uncircumcision was committed unto me, as the gospel of the circumcision was unto Peter;
Contrariwise. So far from adding any new light to ME, THEY gave in THEIR adhesion to the new path on which Barnabas and I, by independent revelation, had entered-namely, the innovation of preaching the Gospel without circumcision to the Gentiles.
When they saw - from the effects "wrought" (Galatians 2:8; Acts 15:12).
Gospel of the uncircumcision - i:e., of the Gentiles, whose circumcision was not to be required.
Was committed unto me - Greek, 'I had been permanently intrusted with, etc., as Peter was with,' etc.
Circumcision was unto Peter. Peter originally opened the door to the Gentiles (Acts 10:1-48; Acts 15:7). But in the ultimate apportionment of spheres, the Jews were assigned to him (cf. 1 Peter 1:1). So Paul wrote to the Hebrews (cf. also Colossians 4:11), though his main work was among the Gentiles. The non-mention of Peter in the list of names in Romans 16:1-27 shows that Peter's residence at Rome, much more primacy, was then unknown. The same appears from the sphere here assigned to him.