Ecclesiastes 10:8-11

8One who digs a pit may fall into it, and one who breaks through a wall may be bitten by a snake.

9One who quarries stones may be injured by them; one who splits logs may be endangered by them.

10If an iron axhead is blunt and a workman does not sharpen its edge, he must exert a great deal of effort; so wisdom has the advantage of giving success.

11If the snake should bite before it is charmed, the snake charmer is in trouble.