The prophet Joel warned the people of Judah about God’s coming judgment—and the coming restoration and blessing that will come through repentance.
From the desolations about to come upon the land of Judah, by the ravages of locusts and other insects, the prophet Joel exhorts the Jews to repentance, fasting, and prayer. He notices the blessings of the gospel, with the final glorious state of the church.
Matthew Henry