Ecclesiastes 10:9-13

Whoso removeth stones shall be hurt therewith; and he that cleaveth wood shall be endangered thereby.

If the iron be blunt, and he do not whet the edge, then must he put to more strength: but wisdom is profitable to direct.

Surely the serpent will bite without enchantment; and a babbler is no better.

The words of a wise man’s mouth are gracious; but the lips of a fool will swallow up himself.

The beginning of the words of his mouth is foolishness: and the end of his talk is mischievous madness.