Isaiah 31:3

Now the Egyptians are men - They are nothing but people; they have no power but such as other people possess. The idea here is, that the case in reference to which they sought aid was one in which “divine” help was indispensable, and that, therefore, they relied on the aid of the Egyptians in vain.

And their horses flesh, and not spirit - There is need, not merely of “physical” strength, but of wisdom, and intelligence, and it is in vain to look for that in mere brutes.

Both he that helpeth - Egypt, whose aid is sought.

And he that is holpen - Judah, that had sought the aid of Egypt. Neither of them would be able to stand against the wrath of God.