Romans 2:29 → Jeremiah 31:33

Paul defines the true Jew as "one inwardly, and circumcision is a matter of the heart, by the Spirit, not by the written code" (Rom 2:29). The contrast between "the Spirit" and "the written code" (Greek gramma, "letter") reproduces Jeremiah's stone/heart contrast: where the old covenant inscribed law on tablets (Exod 31:18), the new covenant writes Torah on the heart (Jer 31:33). Paul fuses Jeremiah's interiorization promise with the heart-circumcision of Deuteronomy 30:6, arguing that the prophetic hope of an obedient heart is fulfilled by the Spirit in the new-covenant believer, Jew or Gentile. The phrase anticipates the explicit "ministers of a new covenant... not of the letter but of the Spirit" of 2 Corinthians 3:6, showing this letter/Spirit antithesis to be Paul's settled reading of Jeremiah 31:33. The verse dismantles any boast in external membership: covenant standing is the Spirit's interior work, not human ceremony. Its telos is that praise "comes... from God" rather than men — the heart written on by God's Spirit is one that finds its approval and joy in God himself, the very delight the new covenant exists to create.