Ecclesiastes 10:10-12

Young's Literal Translation

¹⁰ If the iron hath been blunt, And he the face hath not sharpened, Then doth he increase strength, And wisdom [is] advantageous to make right.

¹¹ If the serpent biteth without enchantment, Then there is no advantage to a master of the tongue.

¹² Words of the mouth of the wise [are] gracious, And the lips of a fool swallow him up.