Ecclesiastes 10:10-12

¹⁰If the iron be blunt, and man do not whet the edge, then must he exert more strength; but the advantage of making it properly sharp is wisdom.

¹¹If the serpent do bite because no one uttered a charm, then hath the man that can use his tongue in charming no preference.—

¹²The words of a wise man's mouth bring grace; but the lips of a fool will destroy himself.