Joel 1:13-15; 2:1-2
Chapter 1
13
Mourning and Supplication
Gird yourselves, O priests, and weep; mourn, O ministers of the altar. Come, spend the night in sackcloth, O ministers of my God! For the house of your God lacks grain and drink offerings.14
Proclaim a fast, call an assembly. Summon the elders, and all who live in the land, into the house of your God, and cry out to the Lord:
15
“What a dreadful day —the day of the Lord, that draws near, and comes as a ruin, from the Almighty!”
Chapter 2
1
The Locust Invasion
Blow the trumpet in Zion, sound the alarm on my holy mountain! Let all who live in the land tremble, for the day of the Lord is near. Yes, the day is quickly approaching,
2
a day of gloom and darkness, filled with clouds and blackness. A vast and mighty army is coming, like dawn breaking over the mountain, such as has never happened before, nor will again in the future.

Commentaries
Mourning and Supplication.
The priests are called to lead a period of repentance. The locust plague that destroys everything in its path signals the terrible “day of the Lord.” With the shortage of shortage, the celebrations and joy in the Lord’s temple also come to an end (16). The prophet shows solidarity with the people suffering from the devastating plague that strikes like fire (19-20).
The Locust Invasion.
The trumpet signals the arrival of the invader on the “holy mountain”—Jerusalem. Now, the destructive advance of the locusts is compared to the movement of an invading army as devastating as the Assyrians. The dense cloud of locusts (cf. Ex 10:14) announces “the day of the Lord,” a day characterized by “darkness and gloom” (2). Darkness and clouds are symbols linked to the Lord in his role as a mighty warrior (Dt 5:22).