Romans 15:8

λέγω γὰρ Χριστὸν διάκονον γεγενῆσθαι περιτομῆς = what I mean is this Christ has been made, etc. διάκονον περιτομῆς is usually understood as “a minister to the Jews, to circumcised people” (cf. Romans 3:30; Romans 4:9), and this seems to me the only intelligible explanation. In exercising this ministry (and He exercised directly no other: Matthew 15:24) Christ was of course circumcised Himself and set from His birth (Galatians 4:4 f.) in the same relation to the law as all who belonged to the old covenant; but though this is involved in the fact that Christ was sent to the Jews, it is not what is meant by calling Him διάκονον περιτομῆς. ὑπὲρ ἀληθείας θεοῦ : in the interest of God's truth (cf. Romans 1:5 : ὑπὲρ τοῦ ὀνόματος αὐτοῦ). The truth of God, as the giver of the promises to the fathers, was vindicated by Christ's ministry; for in Him they were all fulfilled, 2 Corinthians 1:20. τὰς ἐπαγγ. τῶν πατέρων : the promises belonged to the fathers, because they were originally made to them.