Your spoil shall be gathered. The "spoiling" of Assyria would commence with the discomfiture of the great host. In the historical narrative (2 Kings 19:35; Isaiah 37:36) nothing is said of it; but, beyond a doubt, when the host was to a largo extent destroyed, and the remainder fled, there must have been an enormous booty left behind, which the enemies of the Assyrians would naturally seize.
A further spoiling of the fugitives probably followed; and, the prestige of the great king being gone, marauding bands would probably on all sides ravage the Assyrian territory. Like the gathering of the caterpillar.
The "caterpillar" (khasil) is probably the grub out of which the locust develops—a very destructive insect. Shall he run. It would be better to render, shall they run. The word, indeed, is in the singular; but it is used distributively, of the various spoilers.