Judah is seeking help from Egypt, instead of seeking help from God. And Isaiah points out that the help that they need, comes not from this world, but from heaven above. And Egypt is only made up of people, and the resources, referred to here as horses, are only made of flesh.
Egypt and its resources, are therefore, very limited as to what they will be able to do for Judah.
God on the other hand, is the sovereign authority over all of creation and beyond.
God is eternal spirit, and as such has no limitations, but is unlimited and infinite.
When man faces a problem, he has to reach into his bag of earthly resources, and either invent them, or produce them, and logistically supply them, and do this over and over again as the battle rages on, in order to combat or confront the problem, and either win against the problem, or lose to it.
When God faces the problem, the problem is already solved. God merely has to stretch out His hand, and the matter is accomplished.
And when the matter at hand deals with those parties who ignore or are against God, then they are enemies, and they fail and they fall.
The helper, in this instance, refers to Egypt, who is the one helping Judah.
The holpen, refers to the one being helped, namely Judah, who is the one seeking help from Egypt.
Judah is facing Assyria, and their imminent invasion, and has looked to Egypt, for their defense against Assyria. Seeking help from God was not on the table.
And of course the principle here, is the ultimate disaster and failure that will enter into a person’s life, when God is ignored.
Looking to the resources of this world, whether they be political, or military, social, or economic, personal opinions or preferences, all are the same. They are all of the flesh, namely of this world, and are limited in what they can accomplish, and temporary at best. Nothing of this world can provide any solution, any permanent solution, for any or all of the difficulties that anyone will face in this life.
Only God can solve problems, and access to those solutions from God, demands a functioning spiritual life. And of course a functioning spiritual life, demands a daily Bible study, while in fellowship, which are the very basic fundamental ingredients of the spiritual life.