Ecclesiastes 10:8-11

He that diggeth a pit shall fall into it; and whoso breaketh through a wall, a serpent shall bite him. Whoso heweth out stones shall be hurt therewith; and he that cleaveth wood is endangered thereby. If the iron be blunt, and one do not whet the edge, then must he put to more strength: but wisdom is profitable to direct. If the serpent bite before it is charmed, then is there no advantage in the charmer.