What does Isaiah 21:2 mean?
The cryptic vision of an approaching terror continues in this verse (Isaiah 21:1). From a few verses later in the chapter, we know the subject of this oracle is Babylon (Isaiah 21:9). We know from the context of history this terror is the Assyrians coming to put down the Babylonian rebellion against their authority.Isaiah writes that this is a dire vision from the Lord. He is deeply troubled by what he has been shown. The prophet expresses empathy for those who will suffer. There is also disappointment that, once again, hopes that someone will defeat the Assyrians will be thwarted. He has seen those who are traitors betraying their allies. Those who were thought to be friendly will turn on each other. In a sense, Isaiah is burdened by the knowledge that the terrible things to come cannot be stopped.
Commentators note that this passage is difficult to untangle. Scholars debate whether Isaiah is calling the nearby nations of Elam and Media—the Medes—to attack Babylon, or to help Babylon. The Medes and the Persians will defeat Babylon later, in 539 BC. If this prophecy is pointing to 689 BC, when the Assyrians would conquer Babylon, it is less clear whose side Elam and Media were on. The ruler of Babylon who defied the Assyrians was taken in by Elam in 710 BC after his initial defeat. It's possible that Isaiah's oracle is calling these two nations to help bring an end to all the pain caused by either the Assyrians or the Babylonians.