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.
Ver. 10. If the iron be blunt.] Pliny a calls iron the best and worst instrument of man's life, and shows the many uses of it, as in ploughing, planting, pruning, planing, &c., but abominates the use of it in war and murdering weapons. Porsena enjoined the Romans, Ne ferro nisi in agricultura uterentur, saith he, that they should not use iron but only about their husbandry. The Philistines took the like order with the disarmed Israelites, 1Sa 13:19 among whom swords and spears were geasen; shares and coulters they allowed them, but so as that they must go down to the Philistines for sharpening. Gregory compares the devil to these Philistines, blinding and blunting men's wits and understandings, "lest the light of saving truth should shine unto them." 2Co 4:4 These edge tools, therefore, must be whetted by the use of holy ordinances, and much strength put to, great pains taken, virtutibus corroborabitur (so the old translation hath it). But when all is done, he must needs be obtuse acutus, which seeth not that wisdom is profitable to direct; that is, that (whether the iron be blunt or sharp, whetted or not whetted, more strength added or not added) it is wisdom that rectifies all, or the benefit of rectifying is wisdom. "There is none to that," as David said of Goliath's sword.
a Lib. xxxiv, cap. 14.