A Commentary, Critical, Practical, and Explanatory on the Old and New Testaments, by Robert Jamieson, A.R. Fausset and David Brown [1882] at sacred-texts.com
The first chapter describes the desolation caused by an inroad of locusts--one of the instruments of divine judgment mentioned by Moses (Deu 28:38-39) and by Solomon (Kg1 8:37). The second chapter (Joe 2:1-11): the appearance of them, under images of a hostile army suggesting that the locusts were symbols and forerunners of a more terrible scourge, namely, foreign enemies who would consume all before them. (The absence of mention of personal injury to the inhabitants is not a just objection to the figurative interpretation; for the figure is consistent throughout in attributing to the locusts only injury to vegetation, thereby injuring indirectly man and beast). Joe 2:12-17 : exhortation to repentance, the result of which will be: God will deliver His people, the former and latter rains shall return to fertilize their desolated lands, and these shall be the pledge of the spiritual outpouring of grace beginning with Judah, and thence extending to "all flesh." Joel 2:18-3:21 : God's judgments on Judah's enemies, whereas Judah shall be established for ever.
Joel's style is pre-eminently pure. It is characterized by smoothness and fluency in the rhythms, roundness in the sentences, and regularity in the parallelisms. With the strength of Micah it combines the tenderness of Jeremiah, the vividness of Nahum, and the sublimity of Isaiah. As a specimen of his style take the second chapter wherein the terrible aspect of the locusts, their rapidity, irresistible progress, noisy din, and instinct-taught power of marshalling their forces for their career of devastation, are painted with graphic reality.