Matthew Poole and continuators on Daniel 4:16

16 Let his heart be changed from mans, and let a beasts heart be given unto him, and let seven times pass over him .

Let him live seven years as a Beast in mans shape among Beasts of the Field, let him become brutish without humane sense and understanding, and this appeared much also in his outward shape; nailes 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 phansies, but this is a false construction of Gods 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 eat 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 inhumane 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.