What does the verse teach?
Rashi: They said to leave the roots - the interpretation is, your kingship will remain for you. In the end, you will return to it. Malbim - if not for this, it seemed more that kingship will return to his seed, but not to him
What do we learn from "Min Di Sinda Di Shalitin Shemaya"?
Rashi: After you will know that the upper beings rule in the world.
Why did he not explain "the lowliest man will rise against it"?
Malbim: The primary anger was for the image that he made; via it, he intended to nullify Shamayim's decree, i.e. of the four kingdoms that he saw in the first dream. Therefore, kingship was removed from him immediately, so he will know that Hashem rules over people, and they cannot change His decrees. After he recognized that kingship is Hashem's, and his actions via the image did not help. In the end of days, one who is now the lowliest man - the rock cut not by hand - he will be returned to his kingship. Daniel did not want to mention this, lest he flare Nebuchadnetzar's anger against Yisrael.
