Proverbs 26:9
As a thorn goeth up into the hand of a drunkard, so is a parable in the mouth of fools.
Cross-reference
Proverbs 26:7
Parallel
Proverbs 26:7 also says a proverb in a fool's mouth is useless — here it's dangerous, both highlight misuse of proverbs by fools.
Ecclesiastes 10:12
Parallel
Ecclesiastes 10:12 warns that a fool's lips consume him — same theme as the danger of a fool speaking proverbs.