Romans 12:20

ἀλλὰ : On the contrary, as opposed to self-avenging, and even to the merely passive resignation of one's case to God. ἐὰν πεινᾷ κ. τ. λ. Proverbs 25:21 f. exactly as in LXX. The meaning of “heaping burning coals on his head” is hardly open to doubt. It must refer to the burning pain of shame and remorse which the man feels whose hostility is repaid by love. This is the only kind of vengeance the Christian is at liberty to contemplate. Many, however, have referred to 4 Esdr. 16:54 (Non dicat peccator se non peccasse; quoniam carbones ignis comburet super caput ejus, qui dicit: non peccavi coram Domino Deo et gloria ipsius), and argued that the coals of fire are the Divine judgments which the sinner will bring on himself unless he repents under the constraint of such love. But (1) there is nothing said here about the essential condition, “unless he repents”; this is simply imported; and (2) the aim of the Christian's love to his enemy is thus made to be the bringing down of Divine judgment on him which is not only absurd in itself, but in direct antagonism to the spirit of the passage.