A grievous vision; literally, a hard vision; not, however, "hard of interpretation" (Kay), but rather "hard to be borne," "grievous," "calamitous." The treacherous dealer dealeth treacherously; rather, perhaps, the robber robs (Knobel); or, the violent man uses violence (Rosenmüller).
The idea of faithlessness passes out of the Hebrew boged occasionally, and is unsuitable here, more especially if it is the army of Cyrus that is intended. Go up, O Elam. The discovery that Cyrus, at the time of his conquest of Babylon, Bore the title of "King of Ansan," not "King of Persia," coupled with the probability that "Ansan" was a part of Elam, lends a peculiar interest to these words.
Isaiah could not describe Cyrus as "King of Persia," and at the same time be intelligible to his contemporaries, since Persia was a country utterly unknown to them. In using the term "Elam" instead, he uses that of a country known to the Hebrews (Genesis 14:1), adjoining Persia, and, at the time of his expedition against Babylon, subject to Cyrus.
Besiege, O Media. Having given "Elam" the first place, the prophet assigns to Media the second. Eleven years before he attacked Babylon, Cyrus had made war upon Astyages (Istuvegu), King of the Medes, had captured him, and become king of the nation, with scarcely any opposition (see the 'Cylinder of Nabonidus').
Hence the Medes would naturally form an important portion of the force which he led against Babylon. All the sighing thereof have I made to cease. The "sighing" caused by Babylon to the nations, to the captives, and to the kings whose prison-doors were kept closed (Isaiah 14:17), God has in his counsels determined to bring to an end.