Deaf adders may seem very stupid creatures to be teaching lessons to human beings, but they are certainly able to do it. There is quite a variety of deaf adders in the world.
I. Lazy schoolboys and girls are like deaf adders.
II. Hard-headed people are like deaf adders.
III. Hard-hearted people are like deaf adders.
IV. Ungodly people are like deaf adders.
J. N. Norton, The King's Ferry Boat,p. 126.
Reference: Psalms 58 J. Hammond, Expositor,1st series, vol. iv., p. 212.