Shall they, to wit, their enemies, which is plainly implied, carry away to the brook of the willows; unto some brook or river having great numbers of willows growing by it, by which they might convey them to some eminent and strong city built upon the same river. Possibly he means some such river which ran into Euphrates, and so gave them opportunity of carrying their spoils by water unto Babylon. Though the words may be rendered, into the valley of the Arabians; whither the spoils might be first carried, in order to their transportation into Assyria or Chaldea; for part of Arabia lay between Moab and those countries. But the former translation seems better, because these very words are so rendered, Leviticus 23:40.
Related Commentaries of Isaiah 15:7
Isaiah 15:7
7 Therefore the abundance they have gotten, and that which they have laid up, shall they carry away to the brookc of the willows.