Theophylact of Ohrid
Catena Aurea · Lukasevangelium 11
And he was casting out a devil, and it was dumb. And it came to pass, when the devil was gone out, the dumb spake; and the people wondered. But some of them said, He casteth out devils through Beelzebub the chief of the devils. And others, tempting him, sought of him a sign from heaven.
Now he is called κωφὸς, as commonly meaning one who does not speak. It is also used for one who does not hear, but more properly who neither hears nor speaks. But he who has not heard from his birth necessarily cannot speak. For we speak those things which we are taught to speak by hearing. If however one has lost his hearing from a disease that has come upon him, there is nothing to hinder him from speaking. But He who was brought before the Lord was both dumb in speech, and deaf in hearing.