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

Read Ecclesiastes 10:10 Using Other Translations

If the iron be blunt, and he do not whet the edge, then must he put to more strength: but wisdom is profitable to direct.
If the iron is blunt, and one does not sharpen the edge, he must use more strength, but wisdom helps one to succeed.
Using a dull ax requires great strength, so sharpen the blade. That’s the value of wisdom; it helps you succeed.