Jamieson, Fausset & Brown

Now--"For" is the true reading: the apostle is merely assigning an additional motive to Christian forbearance. I say that Jesus Christ was--"hath become" a minister of the circumcision--a remarkable expression, meaning "the Father's Servant for the salvation of the circumcision (or, of Israel)." for the truth of God--to make good the veracity of God towards His ancient people. to confirm the--Messianic promises made unto the fathers--To cheer the Jewish believers, whom he might seem to have been disparaging, and to keep down Gentile pride, the apostle holds up Israel's salvation as the primary end of Christ's mission. But next after this, Christ was sent.