Proverbs 25:22 in the World English Bible
for you will heap coals of fire on his head, and the LORD will reward you.
Context
21 If thine enemy be hungry, give him bread to eat; and if he be thirsty, give him water to drink:
22 For thou shalt heap coals of fire upon his head, and the LORD shall reward thee.
23 The north wind driveth away rain: so doth an angry countenance a backbiting tongue.