John Calvin Commentary Isaiah 2:15

"and upon every lofty tower, and upon every fortified wall," — Isaiah 2:15 (ASV)

And upon every lofty tower. What Isaiah adds about towers and walls is not figurative or metaphorical. We know how people, when they think they are well defended, congratulate themselves that they no longer need God's assistance. Accordingly, under the name of towers and walls, Isaiah mentions the object of false confidence. For if any place seems impregnable, there irreligious people build their nest, so that they may look down from it on heaven and earth, imagining they are placed beyond all the uncertainties of fortune.

Isaiah therefore threatens that when it pleases God to humble people, He will throw down all the defenses on which they place a false confidence. And although these things are not evil in themselves, yet because they receive too large a share of our attention, it is with great propriety that Isaiah sharpens his pen against them.

What Isaiah says about horses and chariots serves the same purpose. For, as Micah tells us, because people have improperly relied on earthly riches, they must be completely deprived of them, so that they may owe their preservation entirely to God's hand (Micah 5:10).

A little earlier, Isaiah had reproved them for the abundance of their horses (Isaiah 2:7). He now addresses them about God's judgment and warns them that, as the only possible way of gaining God's favor, God must take from the Jews all their horsemen, so that they may no longer place sinful reliance on earthly support.