It is often said that the day of the Lord is the major theme of Joel (e.g., Allen, 36). Having already alluded to the connection between the locust invasion and the Day (1:15), Joel returns to that theme in this section. It is not yet fully in evidence, but the Day is close. Therefore the alarm should be sounded throughout Zion. Strong similes are used to describe the relentless march of the insects across the land. They literally create a black darkness as they swarm. They are like an army as they attack (v. 2). The destruction is complete and sudden. The land, which was like the garden of Eden before their attack, is a desolate wasteland after they are gone (v. 3). The locusts come in ranks and files. No obstacle deters them. They even resemble miniature horses—war horses on the attack. The sound they make is reminiscent of battle conditions. They invade every wall and house, every corner (vv. 7-9). To Joel the invasion becomes a powerful metaphor of God's judgment to be expected on his terrible Day. Like the locusts God's judgment cannot be evaded (vv. 10-11).