Romans 12:20-21

20. If therefore, etc. He now shows how we may really fulfill the precepts of not revenging and of not repaying evil, even when we not only abstain from doing injury but when we also do good to those who have done wrong to us; for it is a kind of an indirect retaliation when we turn aside our kindness from those by whom we have been injured. Understand as included under the words meat and drink, all acts of kindness. Whatsoever then may be thine ability, in whatever business thy enemy may want either thy wealth, or thy counsel, or thy efforts, thou oughtest to help him. But he calls him our enemy, not whom we regard with hatred, but him who entertains enmity towards us. And if they are to be helped according to the flesh, much less is their salvation to be opposed by imprecating vengeance on them.

Thou shalt heap coals of fire, etc. As we are not willing to lose our toil and labor, he shows what fruit will follow, when we treat our enemies with acts of kindness. But some by coals understand the destruction which returns on the head of our enemy, when we show kindness to one unworthy, and deal with him otherwise than he deserves; for in this manner his guilt is doubled. Others prefer to take this view, that when he sees himself so kindly treated, his mind is allured to love us in return. I take a simpler view, that his mind shall be turned to one side or another; for doubtless our enemy shall either be softened by our benefits, or if he be so savage that nothing can tame him, he shall yet be burnt and tormented by the testimony of his own conscience, on finding himself overwhelmed with our kindness. ¹

21. Be not overcome by evil, etc. This sentence is laid down as a confirmation; for in this case our contest is altogether with perverseness, if we try to retaliate it, we confess that we are overcome by it; if, on the contrary, we return good for evil, by that very deed we show the invincible firmness of our mind. This is truly a most glorious kind of victory, the fruit of which is not only apprehended by the mind, but really perceived, while the Lord is giving success to their patience, than which they can wish nothing better. On the other hand, he who attempts to overcome evil with evil, may perhaps surpass his enemy in doing injury, but it is to his own ruin; for by acting thus he carries on war for the devil.

¹ Calvin has in this exposition followed Chrysostom and Theodoret. The former part no doubt contains the right view; the following verse proves it, "Overcome evil with good." The idea of "heaping coals of fire" is said to have been derived from the practice of heaping coals on the fire to melt hard metals; but as "the coals of fire" must mean "burning coals," as indeed the word in Proverbs 25:22, whence the passage is taken, clearly means, this notion cannot be entertained. It seems to be a sort of proverbial saying, signifying something intolerable, which cannot be borne without producing strong effects: such is represented to be kindness to any enemy, to feed him when hungry and to give him drink when thirsty, has commonly such a power over him that he cannot resist its influence, no more than he can withstand the scorching heat of burning coals. Of course the natural tendency of such a conduct is all that is intended, and not that it invariably produces such an effect; for in Scripture things are often stated in this way; but human nature is such a strange thing, that it often resists what is right, just, and reasonable, and reverses, as it were, the very nature of things.

It is not true what Whitby and others have held, that "coals of fire" always mean judgments or punishments. The word indeed in certain connections, as in Psalm 18:13; Psalm 140:10, has this meaning, but in Proverbs 25:22, it cannot be taken in this sense, as the preceding verse most clearly proves. There is no canon of interpretation more erroneous than to make words or phrases to bear the same meaning in every place. -- Ed.

Romans 12:20-21
20. Therefore if thine enemy hunger, feed him; if he thirst, give him drink: for in so doing thou shalt heap coals of fire on his head.	20. Itaque si esurit inimicus tuus, pasce illum; si sitit, potum da illi: hoc enim faciens carbones ignis congeres in caput ipsius.
21. Be not overcome of evil, but overcome evil with good.	21. Ne vincaris a malo, sed vincas bono malum.