Yahweh speaks to the people of Babylon. This can be made clear. AT: "See, people of Babylon, a people is coming" (See: [[rc://en/ta/man/translate/figs-explicit]])
This phrase refers to the time when the Medes and Persians conquered Babylon in 539 BC. Here "nation" represents their armies. AT: "the armies of a great nation and many kings" (See: [[rc://en/ta/man/translate/figs-synecdoche]])
Being "stirred up" represents being urged to take action. AT: "are preparing to come from the most distant places on earth" (See: [[rc://en/ta/man/translate/figs-metaphor]] and [[rc://en/ta/man/translate/figs-activepassive]])
The loud noise that the soldiers make is compared to the loud noise of the sea. AT: "The sound that they make is very loud, like the sound of the sea" (See: [[rc://en/ta/man/translate/figs-simile]])
# they are riding on horses, set out in order as men for battle
The phrase "set out in order" means that they have organized themselves and are riding in rows. The phrase "as men for battle" indicates that they are ready to fight. AT: "they are riding on horses in their assigned rows, and they are ready to fight"