The enemy armies appear to be a powerful force that no one can stop. AT: "the nations come rushing in like the mighty waters" (See: [[rc://en/ta/man/translate/figs-simile]])
The word "nations" refers to the armies of those nations. AT: "the rushing of the enemy armies" (See: [[rc://en/ta/man/translate/figs-synecdoche]])
# as the dead weeds on the mountains before the wind ... like weeds whirling before a storm
These two phrases mean the same thing. The enemy armies seem powerful but God will easily stop them and send them away. AT: "like dead weeds on the mountains that the wind blows away ... like weeds that whirl and blow away as a storm approaches" (See: [[rc://en/ta/man/translate/figs-parallelism]] and [[rc://en/ta/man/translate/figs-simile]])
# This is the portion of those
What happens to them is spoken of as if it is a portion that they inherit. AT: "This is what happens to those" (See: [[rc://en/ta/man/translate/figs-metaphor]])
# loot us ... rob us
The word "us" refers to Isaiah and the people of Judah.