I. The powerful irruption and descent which the Medes and Persians should make upon Babylon (v. 1, 2): They will come from the desert, from a terrible land. The northern parts of Media and Persia, where their soldiers were mostly bred, was waste and mountainous, terrible to strangers that were to pass through it and producing soldiers that were very formidable. Elam (that is, Persia) is summoned to go up against Babylon, and, in conjunction with the forces of Media, to besiege it. When God has work of this kind to do he will find, though it be in a desert, in a terrible land, proper instruments to be employed in it. These forces come as whirlwinds from the south, so suddenly, so strongly, so terribly, such a mighty noise shall they make, and throw down every thing that stands in their way. As is usual in such a case, some deserters will go over to them: The treacherous dealers will deal treacherously. Historians tell us of Gadatas and Gobryas, two great officers of the king of Babylon, that went over to Cyrus, and, being well acquainted with all the avenues of the city, led a party directly to the palace, where Belshazzar was slain. Thus with the help of the treacherous dealers the spoilers spoiled. Some read it thus: There shall be a deceiver of that deceiver, Babylon, and a spoiler of that spoiler, or, which comes all to one, The treacherous dealer has found one that deals treacherously, and the spoiler one that spoils, as it is expounded, ch. xxxiii. 1. The Persians shall pay the Babylonians in their own coin; those that by fraud and violence, cheating and plundering, unrighteous wars and deceitful treaties, have made a prey of their neighbours, shall meet with their match, and by the same methods shall themselves be made a prey of.