The dukes of Edom - See Genesis 36:15. It denotes the chieftains, not the kings of Edom.

The mighty men of Moab - The physical strength and great stature of the Moabites are noted in other passages: see Jeremiah 48:29, Jeremiah 48:41.

Canaan - The name in this, as in many passages of Genesis, designates the whole of Palestine: and is used of course with reference to the promise to Abraham. It was known to the Egyptians, and occurs frequently on the monuments as Pa-kanana, which applies, if not to the whole of Palestine, yet to the northern district under Lebanon, which the Phoenicians occupied and called "Canaan."

The dukes of Edom - Idumea was governed at this time by those called אלפים alluphim, heads, chiefs, or captains. See Clarke's note on Genesis 36:15.

Then the dukes of Edom shall be amazed, Of which there were many, see Genesis 36:15 the land being first governed by dukes, as perhaps it was at this time, though in some few years after it had a king, Numbers 20:14 now these, when they heard of the wonderful things that were done for Israel in Egypt, at the Red sea, and in the wilderness, were astonished and surprised, and filled with fear and dread, see Deuteronomy 2:4,

the mighty men of Moab, trembling shall take hold upon them: as did on Balak the king of Moab, and his people, Numbers 22:2, where may be observed a literal accomplishment of this prophecy:

all the inhabitants of Canaan shall melt away; as their hearts did, through fear, when they heard what God did for Israel against the Egyptians and the Amorites, and understood that they were upon the march to their land to invade it and dispossess them of it: see the fulfilment of this prediction in Joshua 2:9 thus when Babylon shall be destroyed, as Pharaoh and his host were, and the people of God saved out of the midst of her, as Israel was, the kings of the earth will stand afar off for fear of her torment, and bewail and lament for her, Revelation 18:9.

"Then are the princes (alluphim, see Genesis 36:15) of Edom confounded; the mighty men of Moab, trembling seizes them; all the inhabitants of Canaan despair." אלים, like אוּלים in 2 Kings 24:15, scriptio plena for אלים, strong, powerful ones. As soon as these nations should hear of the miraculous guidance of Israel through the Red Sea, and Pharaoh's destruction, they would be thrown into despair from anxiety and alarm, and would not oppose the march of Israel through their land.

Then the dukes of Edom shall be amazed; the mighty men of Moab, trembling shall take hold upon them; all the inhabitants of Canaan shall melt away.

15:1-21 This song is the most ancient we know of. It is a holy song, to the honour of God, to exalt his name, and celebrate his praise, and his only, not in the least to magnify any man. Holiness to the Lord is in every part of it. It may be considered as typical, and prophetical of the final destruction of the enemies of the church. Happy the people whose God is the Lord. They have work to do, temptations to grapple with, and afflictions to bear, and are weak in themselves; but his grace is their strength. They are often in sorrow, but in him they have comfort; he is their song. Sin, and death, and hell threaten them, but he is, and will be their salvation. The Lord is a God of almighty power, and woe to those that strive with their Maker! He is a God of matchless perfection; he is glorious in holiness; his holiness is his glory. His holiness appears in the hatred of sin, and his wrath against obstinate sinners. It appears in the deliverance of Israel, and his faithfulness to his own promise. He is fearful in praises; that which is matter of praise to the servants of God, is very dreadful to his enemies. He is doing wonders, things out of the common course of nature; wondrous to those in whose favour they are wrought, who are so unworthy, that they had no reason to expect them. There were wonders of power and wonders of grace; in both, God was to be humbly adored.