Daniel 4:16 - Matthew Poole's English Annotations on the Holy Bible

Let him live seven years as a beast in man's shape, among beasts of the field, let him become brutish, without human sense and understanding: and this appeared much also in his outward shape; nails like claws, and hair like feathers. Some think that he was truly changed into a beast, but this cannot be, for then the Chaldeans would never more have owned or restored him. Others judge that he was not changed at all but in appearance only to the beholders and in their fancies; but this is a false construction of God's works, when the Scripture saith it was truly done. It is probable he was mute, and bellowed only, that he went naked, and bowed, and ate grass among the beasts, with whom his converse was: a dreadful example upon the greatest man on earth, for his brutish and raging tyranny, and inhuman carriage, abasing himself, and abusing his honours and great prerogatives to wickedness and savage cruelty, to be thus forsaken of God and men, and to be made a prodigy and spectacle to the world, and that upon record to all generations.