Because it was desolate. — This is spoken of Israel; yet Israel was to preserve a remnant who should return to their land, and ultimately become the centre of the new covenant. So the desolation of Edom, though ultimately perpetual as far as its nationality is concerned, is not inconsistent with the fact foretold by Amos (Amos 9:12), that a remnant even of Edom should at last be received into the Church.
All Idumea. — It is better to keep the uniform name of Edom. Idumea is essentially the same country but is a more modern name, and when it came into use the boundaries had somewhat changed.