Proverbs 25:22 in the King James Version
For thou shalt heap coals of fire upon his head, and the LORD shall reward thee.
Context
21 If your enemy is hungry, give him food to eat. If he is thirsty, give him water to drink;
22 for you will heap coals of fire on his head, and the LORD will reward you.
23 The north wind produces rain; so a backbiting tongue brings an angry face.