Ecclesiastes 10:8-10

8He who digs a pit [for others] may fall into it, and a serpent may bite him who breaks through a [stone] wall.

9He who quarries stones may be hurt with them, and he who splits logs may be endangered by them.

10If the axe is dull and he does not sharpen its edge, then he must exert more strength; but wisdom [to sharpen the axe] helps him succeed [with less effort].