For he is not a Jew, who is one outwardly; neither is that circumcision, which is outward in the flesh:
All Commentaries on Romans 2:28 Go To Romans 2
Tertullian of Carthage
AD 220
The flesh; and "the Jew which is one inwardly "will be a subject of the self-same God as he also is who is "a Jew outwardly; ".
On exactly the same principle, they consider the special soil of Judaea to be that very holy land, which ought rather to be interpreted of the Lord's flesh, which, in all those who put on Christ, is thenceforward the holy land; holy indeed by the indwelling of the Holy Spirit, truly flowing with milk and honey by the sweetness of His assurance, truly Judaean by reason of the friendship of God. For "he is not a Jew which is one outwardly, but he who is one inwardly.".
Of God introducing the spiritual circumcision.