Now I know that the Lord is greater than all gods - Some think that Jethro was now converted to the true God; but it is very probable that he enjoyed this blessing before he knew any thing of Moses, for it is not likely that Moses would have entered into an alliance with this family had they been heathens. Jethro no doubt had the true patriarchal religion.
Wherein they dealt proudly - Acting as tyrants over the people of God; enslaving them in the most unprincipled manner, and still purposing more tyrannical acts. He was above them - he showed himself to be infinitely superior to all their gods, by the miracles which he wrought. Various translations have been given of this clause; the above I believe to be the sense.
Greater than all gods - See Exodus 15:11. The words simply indicate a conviction of the incomparable might and majesty of Yahweh.
For in above them - i. e. the greatness of Yahweh was shown in those transactions wherein the Egyptians had thought to deal haughtily and cruelly against the Israelites. Jethro refers especially to the destruction of the Egyptian host in the Red Sea.