By saying, that at the voice or sound of horsemen and bowmen, there would be an universal flight, he means, that the enemies would come with such impetuosity, that the Jews would not dare to wait for their presence, but would flee here and there before they were attacked: for the word voice or sound, no doubt, is set here in opposition to wounds. They did swell, we know, with amazing pride; hence the Prophet ridicules that false confidence by which they were so inebriated as not to dread God’s judgment: “The sound alone of enemies,” he says, “will frighten you; so that all the cities, being left by their inhabitants, will easily fall into their hands, for walls will not defend themselves; nay, the gates will be open.” Flee then will every city; that is, all the cities will have recourse to flight. Then it follows, Ascend will they into the clouds, or into thicknesses: this may be applied to the enemies, to shew that they would be so nimble and active as to fly, as it were, to the clouds, and climb the highest rocks. But I prefer to connect this sentence with the former, as intimating, that to ascend the clouds would not be too arduous for the Jews in their anxious flight. Inasmuch as the tops of mountains were often covered with thick trees, in order to form a dark shade, this passage may mean, that they fled to such places. However this may have been, the Prophet here, no doubt, refers to such high situations. Hence, the meaning would be more evident if we retain the word, clouds. As to what is intended, we see that that is clear; which is, that the enemies of the Jews would in swiftness be equal to the eagles while pursuing them; or, what is more commonly thought, that the terror felt by the Jews would be so great, that in their flight they would not seek recesses nigh at hand, but would flee to the highest tops of mountains, and hide themselves there among the trees, as though they had climbed into the clouds. They would ascend into craggy rocks, as they could not think themselves otherwise safe from the attacks of their enemies. ¹²³¹²³     The verbs in this are all in the past tense, as in some former instances. The Prophet had already seen in a vision what he here states, —
   At the voice (or sound) of the rider and of the handler of the bow, Flee did every city; They went into thickets, and into cliffs they climbed; Every city was forsaken, And dwell in them did no man.
   The word for “thickets” means sometimes “clouds.” The verb signifies to be dense, thick, gross, bulky: but the plural noun means a thick wood, as well as a thick or dense mass of vapors, which form clouds. It is rendered “ἄλση, — forests,“ by the Septuagint and Syriac; and “sylvas — woods,” by the Targum. — Ed

He then adds, that every city would be forsaken, so that no one would dwell in them. We see that the Prophet had ever this in view — to rouse the Jews, who had deaf ears and stony hearts, so that they felt no concern for their own calamities, and even boldly despised God, as though they had made a covenant with death, according to what is said in another place. (Isaiah 28:15.) He afterwards subjoins —