Ecclesiastes 10:8-11

8He that diggeth a pit shall fall into it; and whoso breaketh through a fence, a serpent shall bite him.

9Whoso heweth out stones shall be hurt therewith; and he that cleaveth wood is endangered thereby.

10If the iron be blunt, and one do not whet the edge, then must he put to more strength: but wisdom is profitable to direct.

11If the serpent bite before it be charmed, then is there no advantage in the charmer.