en_tn/isa/02/15.md

high tower ... impregnable wall

These refer to things people would build around their cities so they could defend themselves against their enemies. They are a metaphor for the Israelites' pride and belief that they had no need for Yahweh and could stand against any punishment Yahweh would mete out to them for their sins. (See: rc://en/ta/man/jit/figs-metaphor)

impregnable wall

"wall that nothing can break down or go through"