‘The burden of Egypt. Behold Yahweh rides on a swift cloud, and comes to Egypt. And the idols of Egypt will be removed at his presence, and the heart of Egypt will melt in the midst of it. And I will stir up the Egyptians against the Egyptians, and they will fight every one against his brother, and every one against his neighbour, city against city, and kingship against kingship.'
The idea of Yahweh riding triumphantly on the clouds is found in Psalms 18:10-15; Psalms 104:3, but Baal was regularly known as ‘the rider on the clouds' and the concept was thus a common one and probably borrowed from there. The idea is of Yahweh's sovereignty over the world as he looks down on men, and of His heavenly and rapid approach.
Coming to Egypt in His power He will throw it into disarray. The idols will be thwarted at His presence, the people will be in fear and totally demoralised. This idea will be amplified in Isaiah 19:16-25, where Yahweh will conquer Egypt for Himself..
And He will cause civil war to break out, Egyptian against Egyptian, and brother against brother, and city and petty king will war against each other. And this was a true picture of Egypt prior to their invasion by Cush and partly explains the success of that invasion. It was, however, still strong enough to dissuade Assyria from advancing across its borders, even though they did have to be bought off with a gift of horses. But the nations who sought Egypt's help saw the Cushites as excessively powerful precisely because they had defeated Egypt, for the nations had not appreciated the dire position that Egypt was in. In their eyes only a super-race could have conquered Egypt.