Proverbs 26:2-4

New International Version - UK

² Like a fluttering sparrow or a darting swallow,
    an undeserved curse does not come to rest.
³ A whip for the horse, a bridle for the donkey,
    and a rod for the backs of fools!
⁴ Do not answer a fool according to his folly,
    or you yourself will be just like him.