This is called a vision because it is one, an inner seeing, and the whole scene is a movement within a person rather than a quarrel between nations. Edom is the outer man bound to the senses, the reddened, earth-ruled state that must be overturned before the desired state can stand. The battle is the inner struggle by which imagination rises against the appearances that deny it.
The rumour heard from the Lord and the ambassador sent are the desire itself, arriving twice, and a doubled report is a settled thing. When an inner scene is raised to full vividness and confirmed a second time, it is fixed as law and must come to pass; the sense-bound state cannot hold against it. The command to arise is the imagination stirring itself to act. In plain words, a desire made vivid and confirmed within becomes a certainty, and once it is that sure, the old condition it opposes gives way.