After the superscription, Joel can be divided into six major sections: 1:2-20; 2:1-11; 2:12-17; 2:18-27; 2:28-32; 3:1-21.
Verse 1 identifies the author of the book as Joel, the Son of Pethuel. Nothing further is known about the author except that he received the word of Yhwh recorded in this book.
Joel 1:2-20 recounts a plague of locusts that have descended upon the Israelites in Judah. Joel begins by calling out to the elderly to confirm that this locust plague was like nothing they or their fathers had ever experienced. This would be a plague that would be recounted generation after generation due to its severity. The drunkards are told to weep because there is no wine to drink. But more seriously, this judgment prevents them from worshipping God through the grain and drink offerings. Their sin has brought a judgment that deprived them of proper worship. In verse 15 Joel identifies this plague as the day of Yhwh. He says the day of Yhwh is near, which doesn’t mean that the day of Yhwh is something other than the locust plague. Rather, the Day of Yhwh is so near that it is upon them.
The second major section 2:1-11 has occasioned debate. Does it refer to (1) a locust invasion in Joel’s day that prefigures the eschatological day of Yhwh, (2) a now past military invasion described under the figure of locusts, (3) an eschatological locust plague, (4) an eschatological military invasion. It is best to understand this passage to be about locusts; they are described as “like war horses,” “like warriors,” and “like soldiers”—which indicates that they are not themselves horses, warriors, or soldiers. It is unlikely that chapter 2 is a continued description of the locust plague recounted in chapter 1 since the verbs in chapter 1 indicate that Joel was referring to a past event, whereas in chapter 2 the verbs indicate that he is speaking of a future event. In addition, the locusts described in chapter 2 will be unprecedented: “their like has never been before, nor will be again after them through the years of all generations” (2:3). In fact, there are several elements in the passage that indicate these are not normal locusts: they are opposed with weapons, and they are described not as destroying crops but as invading cities.
The third major section (2:12-17) is a call to repentance. No one can endure the judgment of the day of Yhwh (2:11) and therefore repentance is called for. This repentance is not to be merely external (the rending of garments) but internal (the rending of hearts). Repentance from the heart is what the first great commandment demands, and a new heart is what the new covenant promised. The hope that God would receive their repentance is based on God’s declaration to Moses of his character. And yet God’s grace and mercy are not presumed upon: “Who knows” (2:14). Note also that Joel highlights as the foremost blessing of forgiveness the restoration of true worship (the ability to offer grain and drink offerings). Thus, all the people, from the oldest to the youngest (and including those normally exempt from such gatherings, the bride and bridegroom [cf. Dt 24:5]) are to gather to beg for mercy. Their main concern, Joel indicates, is to be God’s glory (2:17).
Evidently the Israelites responded with repentance because the fourth section of the book describes God’s response to their repentance (2:18-27). While some of the promised restoration seems to be directed at restoring the land after the locust plague (e.g., “I will restore to you the years that the swarming locusts has eaten,” 2:25), other promises were not fulfilled in Joel’s day: “And my people shall never again be put to shame.” Israel would still face conquest by Babylon and Rome; Israel would again be put to shame. There is in this section a telescoping of the now past and the still future.
The fifth section of the book (2:28-32) looks forward to the eschatological gift of the Spirit, the ultimate day of Yhwh judgment on the whole earth, and the hope of salvation for those who call upon the name of Yhwh. That a remnant will be saved has already been prophesied by Obadiah. Joel turns to the judgment of the nations in the sixth section (3:1-21) of the book. This section recounts the sins the nations surrounding Judah have committed against God’s people Israel. As a result, God will judge the nations. Some of the judgments described seem to have already happened (3:4-8), while other judgments seem to be eschatological (3:1-3, 9-17, 19, 21). As a counterpoint to this judgment, God promises eschatological blessing to Judah and Jerusalem that is described in terms of a reversal of the locust judgment described in chapters 1 and 2.
 The first section is recognized by Garret, Dillard, Stuart, Crenshaw, Tully, and Nass. The second section is recognized by Garrett, Stuart, Crenshaw, Hubbard, Tully, Barker, and Nass (as a subjection of 2:1-17). The third section is recognized by Stuart, Crenshaw, Hubbard, Tully Barker, and Nass (as a subjection of 2:1-17). The fourth section is recognized by Stuart, Crenshaw, Hubbard, Tully, Barker, and Nass. The fifth section is recognized by Garrett, Stuart, Finley, Crenshaw, Hubbard, Tully, Barker, and Nass (as a subsection of 2:28-3:21). The sixth section is recognized by Garrett, Stuart, Finley, Hubbard, Tully, Barker, and Nass (as two subsections of 2:28-3:21).
 Bell, The Theological Messages of the Old Testament Books, 384-85; Barker, ZECOT, 75-77; Harman, ESVEC, 268.
 Patterson, REBC,.
 Grisanti, “The Book of Joel,” in The World and the Word, 425-26; cf. Busenitz, MC, 116.
 Tully, Reading the Prophets as Christian Scripture, 269; Busenitz, MC, 113-15.
 Grisanti, “The Book of Joel, 425.
 Garrett, NAC, 333; Nass, CC, 203. If the locust plague in chapter 2 is considered to be the same as that of chapter 1, it would need to be a second wave of locusts.
 Nass, CC, 216. These are two elements from a series of three lists that Nass presents: “Features of the Army that Do Not Fit Perfectly with Locusts,” “Features of the Army that Do Not Fit Perfectly with Human Soldiers,” and “Features of the Army that Do Not fit Perfectly with Locusts or Human Soldiers.” Under the last heading Nass lists, “Fire burns before them”; “The earth and heavens shake before them”; “The sun, moon, and stars go dark before them.” Nass concludes from this data that Joel 2:1-11 refers to a composite of the day of Yhwh throughout history, culminating in the eschatological day of Yhwh. But it is more likely that Joel 2 is describing the same events that Revelation describes as the first, fourth, and fifth trumpet judgments.
 Michael P. V. Barrett, “Pentecost and Other Blessings: Joel 2:21–28,” Puritan Reformed Journal 12, no. 2 (2020): 8–9. Since the two preceding sections of judgment refer to a near and an eschatological judgment, it makes sense for the description of restoration to include both near and eschatological restoration.
 There is some debate about what it would mean for the sun to be turned to darkness and the moon to blood “before the great and awesome day of Yhwh comes.” These seem to describe the kind of events that would characterize the day of Yhwh. There are two possible solutions. (1) Some note that the preposition translated before can simply mean “in the presence of.” Thus, a temporal meaning is not necessary here and should not be advocated. Busenitz, MC, 190-91; cf. Stuart, WBC, 257. Against this, when לִפְנֵי בּוֹא are used together, a temporal meaning of before is always indicated (1 Sam 9:15; 2 Sam 3:35; Eze 33:22; Mal 4:5). Nass, CC, 448. (2) Others note that the Day of Yhwh is a multifaceted event and that the phrase may be used of a specific part of the overall day, thus allowing for the darkened sun and blood-red moon to be both part of the overall day of Yhwh and yet precede the specific aspect designated Day of Yhwh in these verses. Finley, WEC, 75; Blaising, “A Pretribulation Response,” in Three Views on the Rapture, 246–47; Fanning, Revelation, ZECNT, 270, n. 1. Some would even argue that the fuller phrase “the great and awesome day of Yhwh” is “a technical expression that refers to the last half of the seventieth week [prophesied in Daniel 9].” Alan D. Cole, “A Critique of the Prewrath Interpretation of the Day of the Lord in Joel 2–3,” Detroit Baptist Seminary Journal Volume 9 (2004): 49.
 See Tully, Reading the Prophets as Christian Scripture, 272.