cast them down - that is, predict that they shall be cast down (so Jer 1:10). The prophet’s word was God’s, and carried with it its own fulfillment.
daughters of ... nations - that is, the nations with their peoples. Egypt is to share the fate of other ancient nations once famous, now consigned to oblivion: Elam (Eze 32:24), Meshech, etc. (Eze 32:26), Edom (Eze 32:29), Zidon (Eze 32:30).