The prophet ordered a trumpet (Heb. shophar, ram's horn) to be blown in Zion (Jerusalem), specifically on the temple mount, to sound an alarm (cf. Jer. 4:5-6; Ezek. 33:2-6).18This shophar was the ancient equivalent of an air raid siren. The day of the Lord was coming, and all the inhabitants of the city should tremble. That day would be a time of foreboding evil, symbolized by a very overcast sky. It is interesting that a plague of darkness followed a locust plague in Egypt (Exod. 10). Darkness and clouds are a common figure for judgment and destruction in the Old Testament (e.g., Jer. 13:16; Ezek. 30:3, 18; 32:7-8; 34:12; Amos 5:18-20; Zeph. 1:15). They are often associated with Yahweh in His role of mighty, victorious warrior (cf. Deut. 4:11; 5:22-23; Ps. 18:9, 11; 97:2). Joel could see a gigantic army spread over the horizon like the dawn. (Was the attack coming from the East, the direction of the dawn?). He said there never had been anything like this day nor would there be after it, even the plagues in Egypt. This may be hyperbole, or this day may refer to the Great Tribulation, when the Jews will experience their worst ever attack. Joel said this attack was near, either in the near future in his day or relatively near from his perspective as a prophet (cf. 2 Pet. 3:8).
Many scholars take this passage as predicting an invasion of Jerusalem by some ancient enemy of Israel such as Assyria or Babylonia in the relatively near future.19In favor of this view is the reference to the invasion being near (v. 1). Against it is the statement of its uniqueness in all of history (v. 2). Others view 2:1-11 as a further description of the locust plague that Joel described in chapter 1.20This seems unlikely since the locust plague of chapter 1 was past, but the attack in 2:1-11 was future. I think it probably refers to an attack by some enemy in Joel's day in view of what follows.
