Joel 2:1-17 A Call To Repentance.
Again the prophet speaks of a day of the LORD which is “at hand” (v. 1). It would be a time of darkness, punishment coming from a people “great and strong” (v. 2), whose appearance was like nothing they had seen before, “like the appearance of horses” (v. 4), “with a noise like chariots…like the noise of flaming fire” (v. 5). They are a disciplined army before whom the people will writhe in pain (vv. 6-9). The land would go from being like the garden of Eden to “a desolate wilderness” (v. 3). Even the earth itself would quake and the heavens tremble (v. 10). They are the LORD’s army to execute His word (v. 11).
Given all the above, Joel calls on the covenanted people to repent-a turning to the LORD with the whole heart or core, “with fasting, with weeping, and with mourning” (v. 12). A rending of the heart is more important than externals. They are commanded to return to the LORD because “He is gracious and merciful, slow to anger, and of great kindness; and He relents from doing harm” (v. 13), and may reward them with blessing (v. 14). He calls the elders and the people together for this solemn activity (vv. 15-16), including the priests (v. 17a). Then the nations would see the LORD as Israel’s God (v. 17b).