Here we see very clearly that the tree in his dream points to a human being. It concerns a human being who needs to experience that whoever exalts himself will be humbled by God. His glory is even broken down so far that for quite some time he will resemble no more than an animal. For further explanation, see Daniel 4:23–26.
16 Let his mind be changed from a man’s, and let a beast’s mind be given to him; and let seven periods of time pass over him.