Proverbs 29:9
"If a wise man contendeth with a foolish man, whether he rage or laugh, there is no rest."
Cross References (ranked by relevance)
Proverbs 26:4
Answer not a fool according to his folly, lest thou also be like unto him.
Ecclesiastes 10:13
The beginning of the words of his mouth is foolishness: and the end of his talk is mischievous madness.
Matthew 7:6
Give not that which is holy unto the dogs, neither cast ye your pearls before swine, lest they trample them under their feet, and turn again and rend you.