Romans 12:20 - "On the contrary: "If your enemy is hungry, feed him; if he is thirsty, give him something to drink. In doing this, you will heap burning coals on his head."
Proverbs 25:22 - "In doing this, you will heap burning coals on his head, and the LORD will reward you."
Do these two verses have the same contextual meaning or are Paul and the author of Proverbs saying different things? And what might the meaning be given their context?
It seems that the issue here may be due to differing metaphorical purposes of burning coals.
Coals can be used to burn and harm, but they can also be used to resharpen and temper as in a forge.
From looking at the context of the verse from Paul, it would seem that his usage of the quote would have the latter purpose of to temper or reforge. Earlier he says:
Romans 12:9 - "Love must be sincere. Hate what is evil; cling to what is good"
I should think that doing good to one's enemies for the mere purpose of actually doing them harm later wouldn't be very "sincere."
The author of Proverb's contextual meaning on this verse seems to be more likely the former (harm) than the latter (tempering). This is from his earlier verse:
Proverbs 25:15 - "Through patience a ruler can be persuaded, and a gentle tongue can break a bone."
"Breaking bone" seems to have more in common with doing damage to one's enemies than bringing them into a state of righteousness. In addition, the verse in Proverbs has the the part, "and the LORD will reward you." added on where Paul does not. This statement of contrast with the burning coals again makes me think that he was meaning the coals would undermine or harm one's enemies. Though, it is entirely possible that the two authors could have been saying the same thing.
Paul often cites passages from the scriptures, as he does here. His intention is to encourage charity, as does the passage he is citing from Proverbs.
Romans 12:20-21:
Rather, "if your enemy is hungry, feed him; if he is thirsty, give him something to drink; for by so doing you will heap burning coals upon his head." Do not be conquered by evil but conquer evil with good.
Proverbs 25:21-22:
If your enemy be hungry, give him food to eat, if he be thirsty, give him to drink; For live coals you will heap on his head, and the LORD will vindicate you.
The reference to "burning coals on his head" seems rather odd and to a modern reader implies quite the opposite to charity, instead the desire to inflict injury. This is explained by Kenneth Samuel Wuest here. In biblical times an oriental needed to keep the hearth fire going in order to provide warmth and for cooking. If it went out he had to go to a neighbour for some live coals, which he would carry on his head back to his home. If enough coals are heaped on his head, the man would be sure to get home while they were still burning. So, heaping coals on a man's head met a need just as feeding him and giving him drink did.
Another view is less charitable. It suggests taking revenge by showing love, causing the enemy to feel pangs of anguish, like the pain of fire, for having wronged you. But not only is this unworthy, it also does not explain the quite specific reference to coals on the head.
Sometimes Paul uses Old Testament passages out of context, but in this case both passages recommend charity.
Coals when burning fire red and this is not literal but when you do good to an enemy or someone that hates you they become embarrassed and their face turns red because we are to imitate Christ. The woman caught in adultery, what did J esus say to the leaders,:who is without sin cast the first stone and they all walked away embarrassed. Now Jesus was trying to teach them this, I desire mercy not sacrifice.
