Ecclesiastes 10:8-10

New International Version - UK

⁸ Whoever digs a pit may fall into it;
    whoever breaks through a wall may be bitten by a snake.
⁹ Whoever quarries stones may be injured by them;
    whoever splits logs may be endangered by them.

¹⁰ If the axe is dull
    and its edge unsharpened,
more strength is needed,
    but skill will bring success.