The immediate occasion for the prophecy is a devastating locust plague and accompanying drought, which Joel uses as both a literal and symbolic warning. Joel ’s message includes a call to repentance, warnings of the “Day of the Lord,” and prophecies concerning judgment and restoration.

The theme of Joel is the Day of the Lord. It permeates all parts of Joel’s message, making it the most sustained treatment in the entire OT (1:15; 2:1; 2:11; 2:31; 3:14). The phrase is employed 19 times by 8 different OT authors (Is. 2:12; 13:6, 9; Ezek. 13:5; 30:3; Joel 1:15; 2:1, 11, 31; 3:14; Amos 5:18 [2x], 20; Obad. 15; Zeph. 1:7, 14 [2x]; Zech. 14:1; Mal. 4:5).