“Thus will I make Mount Seir an astonishment and a desolation, and I will cut off from it the one who passes through and the one who returns. And I will fill his mountains with his slain. In your hills and in your valleys and in all your watercourses they will fall who are slain with the sword. I will make you into perpetual desolations, and your cities will not be inhabited, and you will know that I am Yahweh.”
This is a clear contrast to what has happened to Israel. Compare Ezekiel 36:4. The hills and the valleys and the watercourses of Israel had been desolated. They had been made a desolate waste and their cities had been forsaken. They had become a prey and a derision. And Edom had taken advantage of it. Now they will suffer similarly themselves. Thus will they know Who Israel's God is.
‘And I will cut off from it the one who passes through and the one who returns.' A Hebraism to signify everyone without exception.
‘I will make you into perpetual desolations.' Compare Isaiah 34:5-15. It is the final sentence from which there is no recovery.