Proverbs 25:20-22

New Century Version

²⁰ Singing songs to someone who is sad
    is like taking away his coat on a cold day
    or pouring vinegar on soda.

²¹ If your enemy is hungry, feed him.
    If he is thirsty, give him a drink.
²² Doing this will be like pouring burning coals on his head,
    and the Lord will reward you.