“Dumb dogs, they cannot bark,” (Isaiah 56:9)
The dog is a picture of the preacher in whom there is watchfulness and faithfulness. He is on guard by day and by night, watching and barking. The dog is a faithful animal. But here there are dumb dogs who cannot bark at the thieves, that is, they cannot reprove and rebuke false preachers, they do not protect the smug common people but permit the ungodly preachers to rage against the wretched common people.
-Martin Luther
Luther’s Works, 17: Lectures on Isaiah: Chapters 40-66, ed. Jaroslav Jan Pelikan, Hilton C. Oswald, and Helmut T. Lehmann (Saint Louis, MO: Concordia Publishing House, 1999), 265.
