The prophet is describing the arrival of the army. There is an uproar as many people are coming together. Cyrus’s armies were made up of mixed peoples from many nations. Cyrus had conquered different states of Persia one after the other, enlarging his army step by step. As the Lord once brought the Assyrians against Judah, he is now mustering the Medes against Babylon.
4 On entend une rumeur sur les montagnes, Comme celle d'un peuple nombreux; On entend un tumulte de royaumes, de nations rassemblées: L'Eternel des armées passe en revue l'armée qui va combattre.