He is not a Jew; a right or true Jew, who is heir of the promises made to the fathers. That is one outwardly; the word only is to be understood: see 1 Corinthians 1:17. Neither is that circumcision; the right and true circumcision, which God principally requires, and is available unto salvation: that circumcision is not much to be accounted of which is only the cutting off an outward skin.
Related Commentaries of Romans 2:28
Romans 2:28
28 For he is not a Jew, which is one outwardly; neither is that circumcision, which is outward in the flesh: