Apparently quoted from memory from Numbers 21:28; Numbers 24:17, except the first clause; the application, however, is peculiar to this passage. They that fled, etc.; rather, The fugitives stand without strength in the shadow of Heshbon.
There is a difficulty here, for, according to Numbers 24:2, the hostile raid into Moab started from Heshbon. Surely the fugitives would not think of escaping northwards, much less would they be able to elude the vigilance of the foe and reach Heshbon.
But it is not surprising that the author of so long a poem should now and then make a slip; the author of the Book of Job is sometimes inconsistent with the Prologue, and verse 2 is as far away from the passage before us as the Prologue of Job is from Job 19:18.
Nor can we be absolutely certain that our prophecy is exactly as Jeremiah wrote it. Shall come forth; rather, hath come forth (or, cometh forth). From the midst of Sihon. Sihon being, perhaps, regarded as the leader and representative of his warriors.
The corner of Moab; rather, the sides (literally, side, used collectively) of Moab. The tumultuous ones; literally, sons of tumult, a poetical phrase for warriors. The prophet has substituted the more common word shaon for its synonym sheth.