If the iron is blunt, and he does not sharpen the edge, then must he use more strength: but wisdom helps one to succeed.
All Commentaries on Ecclesiastes 10:10 Go To Ecclesiastes 10
George Leo Haydock
Made blunt. After being repeatedly sharpened, (Calmet) it will be more difficult to cut with it, and will expose the person to hurt himself, ver. 9. (Haydock)
Man, since original sin, is in a similar condition.
Wisdom. The wise perform great things even with bad tools. Hebrew, "wisdom is the best directress. "(Calmet)