Verses 21-22 form a unit in which verse 22 is the reason given for following the advice of verse 21. Paul cites these verses in Rom 12.20, omitting the second line of verse 22.

“If your enemy is hungry, give him bread to eat”: “Enemy” is literally “one who hates you,” but some translators make the term plural. “Bread” is used generally for “food,” and in many areas “food” will serve better in translation than “bread”, which is sometimes little known and seldom eaten. So we may say, for example, “If your enemy [or, the one who hates you] is hungry, give him something to eat.”

“And if he is thirsty, give him water to drink”: This line is parallel to the first in form and meaning.

Quoted with permission from Reyburn, William D. and Fry, Euan McG. A Handbook on Proverbs. (UBS Helps for Translators). New York: UBS, 2000. For this and other handbooks for translators see here .