John Calvin Commentary Joel 2:25

"And I will restore to you the years that the locust hath eaten, the canker-worm, and the caterpillar, and the palmer-worm, my great army which I sent among you." — Joel 2:25 (ASV)

The Prophet confirms what he had previously said, and states the opposite—that God can as easily restore a rich fruitfulness to the land as he had before made it barren by sending devouring insects. I will give you years, (for the other years,) he says; and so that the Jews could more fully understand that all this was in God’s hand, he expressly declares that the cankerworms, the chafers, and the locusts were his army and, as it were, his hired army, whom he had employed as it seemed good to him.

The spoilers, then, that had destroyed the whole produce of the land, were, as the Prophet declares, the messengers of God. It was not, he says, by chance that the locusts, or the cankerworms, or the chafers came; but God hired these soldiers; they were his forces and his army to distress the whole people, then famine and want consumed them.

It is not then for no reason that the Prophet mentions here that these destructive insects were God’s army; it is to show more fully what is promised here, for God, who had by this army devoured the whole produce of the land, can now easily restore abundance to replace the barrenness of past years.

Now, when anyone lays down his arms, the land is afterwards cultivated and produces its usual fruit; so the Lord also now shows that the land had been barren because he had sent out his army, that laid waste its whole produce. But now, he says, when I restore you to favor, there will be no army to devour your fruit: the land then will nourish you, for there will be nothing to prevent you from receiving its usual produce.

Had the Jews not been assured that the land had been barren because the locusts, and the chafers, and the cankerworms were the army that the Lord had prepared, they might have always dreaded these spoilers: “Surely the locusts will spring up, the chafers and the cankerworms will come, to devour all the fruit.” The Prophet shows that this did not happen by chance: “Now then, when God is reconciled to you, the land will yield its increase, and nothing will hinder you from enjoying its abundance.”

By calling this army great, he shows that God does not need strong forces to subdue men; for when he prepares locusts and insects, which are only small things, they snatch food from the mouths of men and leave them in need. Though no one draws a sword against them, they still pine away with hunger. The Prophet then derides here the arrogance of men and shows that God does not need to do much when he intends to reduce them to nothing.