Joel 2:11

It now becomes clear that Yahweh is leading this army against Jerusalem. Normally the Lord fought for His people, but here Joel saw Him leading an army against them. He is the one who is directing the soldiers with His voice. His host is both numerous and strong. The day of this attack, the day of the Lord, is great and awesome, and no one can withstand it (cf. Malachi 3:2; Malachi 4:5).

Some interpreters regard the description of the locust plague in Joel 2:1-11 as simply another description of the same locust plague as the one described in chapter 1, or another locust plague in Israel’s past history. Others take this description as an allegory picturing Israel’s traditional enemies. Still others view it as picturing the eschatological day of the Lord in which the Lord Himself will come with His heavenly army in holy war against evil. [Note: E.g., idem, p. 278.] Many amillennialists take this view. The view that seems best to me, and to many other commentators, is that it is a metaphor based on the past locust plague. Joel used the past locust invasion as a harbinger of an impending human invasion by an undesignated foreign foe.