Proverbs 25:21-23

Complete Jewish Bible

²¹ If someone who hates you is hungry, give him food to eat;
    and if he is thirsty, give him water to drink.
²² For you will heap fiery coals [of shame] on his head,
    and Adonai will reward you.
²³ The north wind brings rain
    and a backbiting tongue, angry looks.