15. And upon every lofty tower What he adds about towers and walls is not figurative or metaphorical. We know how men, when they think that they are well defended, congratulate themselves that they no longer need the assistance of God. Accordingly, under the name of towers and walls Isaiah mentions the object of false confidence; for if any place seem to be impregnable, there do irreligious men build their nest, that they may look down from it on heaven and earth; for they imagine that they are placed beyond all the uncertainties of fortune. Isaiah therefore threatens that, when it shall please God to humble men, he will throw down all the defenses on which they place a false confidence. And although those things are not in themselves evil, yet because they receive too large a share of our attention, it is with great propriety that Isaiah sharpens his pen against them.
To the same purpose is what he says about horses and chariots; for, as we are told by Micah, because men have improperly relied on earthly riches, they must be altogether deprived of them, that they may owe this preservation entirely to the hand of God. (Micah 5:10.) A little before, he had reproved them for the abundance of their horses (verse 7); he now addresses them about the judgment of God, and warns them that, as the only possible way of gaining the favor of God, he must take from the Jews all their horsemen, that they may no longer place sinful reliance on earthly support.