Jamieson, Fausset and Brown on Jeremiah 51:27

27. (Jr 50:29). As in Jr 51:12 the Babylonians were told to "set up the standard," so here her foes are told to do so: the latter, to good purpose; the former, in vain.

Ararat--Upper or Major Armenia, the regions about Mount Ararat.

Minni--Lower or Lesser Armenia. Rawlinson says that Van was the capital of Minni. It was conquered by Tettarrassa, the general of Tetembar II, the Assyrian king whose wars are recorded on the black obelisk now in the British Museum.

Ashchenaz--a descendant of Japheth (Ge 10:3), who gave his name to the sea now called the Black Sea; the region bordering on it is probably here meant, namely, Asia Minor, including places named Ascania in Phrygia and Bithynia. Cyrus had subdued Asia Minor and the neighboring regions, and from these he drew levies in proceeding against Babylon.

rough caterpillars--The horsemen in multitude, and in appearance bristling with javelins and with crests, resemble "rough caterpillars," or locusts of the hairy-crested kind (Na 3:15).