“And you son of man, prophesy to the mountains of Israel, and say, ‘You mountains of Israel, hear the word of Yahweh. Thus says the Lord Yahweh. Because the enemy has said against you, “Aha!”, and “The ancient high places are ours in possession”.
Having spoken words of doom to Mount Seir, Yahweh now spoke to the mountains of Israel. He gave as the background against which He was going to work in restoration the cynicism of Edom, which reflected on Himself. Firstly they had said, “Aha!” in a knowing way. They had cast doubts on what Yahweh was doing, and had hinted that He was powerless and unable to help His people. And secondly they had claimed that Yahweh's inheritance was theirs to take possession of.
That they recognised that they were acting against Yahweh comes out in that they saw themselves as taking possession of ‘the ancient high places'. This was ironic. To them the ancient high places were the heart of Israel's religion (compare 2 Chronicles 32:12; Isaiah 36:7 for a similar misconception). They had seen the fervid activity there and had thought that it was central to Yahwism. Now they gloated, they and their gods would take possession of them. The use of ‘ancient' might suggest that they felt that Israel and Yahweh had usurped them in that they were there before Israel arrived. So this was intended to be a direct attack on Yahweh.
There were of course ancient high places such as at Bethel, Shechem, Gibeon and Gilgal, to name but four, which had had an honourable (as well as a dishonourable) history (see Genesis 31:13; Genesis 35:7; Joshua 24:1; Joshua 24:25-26; 1 Samuel 1:3; 1Sa 9:13-14; 1 Samuel 9:19; 1 Samuel 10:8; 1 Samuel 11:15; 1 Kings 3:4). They were local sanctuaries where men had felt that they could meet with God and offer sacrifices other than before the tabernacle, probably places where they considered that God had recorded His name (Exodus 20:24). And some therefore see this verse as indicating a deliberate attempt by Edom to take over the genuine ancient sanctuaries of Judah and Israel. Then ‘ancient' is seen as signifying that they had been given to them by Yahweh long ago so that it was blasphemy to seize them. But the ‘high places' had become a source of Israel's downfall, as Moses had realised that they would, and elsewhere in Ezekiel ‘high places' always has a bad sense, so that that would suggest we see it as having the same sense here.
Others however see ‘high places' here as simply indicating the hills and mountains of Israel (compare Amos 4:13; Micah 1:3; Habakkuk 3:19) which Edom purposed to take over, seeing the verse as indicating Judah's longstanding right to be there as having been given the land by Yahweh. Its use elsewhere in Ezekiel, however, tends to be against this interpretation.