"all that I command him": (He will not change the order of My words) — first things first, second things, afterwards.
(Devarim 18:19) "And it shall be, the man who will not heed My words": There are three whose death is at the hands of Heaven: one who suppresses his prophecy, like Yonah the son of Amittai; one who dismisses the words of a prophet, as did the colleague of Michah (viz. I Kings 20:35), and a prophet who transgresses his own prophecy, as did Iddo, viz. (I Kings 13:21). And there are three whose death is at the hands of beth-din: one who prophesies what he did not hear (from G-d), like Tzidkiyahu ben Cna'anah (viz. I Kings 22:24); and what was not spoken to him, like Chananiah ben Azur, who heard things from the mouth of Jeremiah, who prophesied in the upper marketplace and went and prophesied in the lower marketplace (viz. Jeremiah 28); and one who prophesies in the name of idolatry, i.e., "This is what the idol says" — even if what he said was consistent with the halachah, to rule unclean what was unclean, and clean what was clean — it being written (Ibid. 20) "But the prophet who shall presume, etc."