Ecclesiastes 10:8-12

⁸He that diggeth a pit falleth into it; and whoso breaketh down a hedge, a serpent biteth him.

⁹Whoso removeth stones is hurt therewith; he that cleaveth wood is endangered thereby.

¹⁰If the iron be blunt, and one do not whet the edge, then must he apply more strength; but wisdom is profitable to give success.

¹¹If the serpent bite before enchantment, then the charmer hath no advantage.

¹²The words of a wise man's mouth are gracious; but the lips of a fool swallow up himself.