17 Let the nations be awake, and come to the valley of Jehoshaphat: for there I will be seated as judge of all the nations round about.

18 Put in the blade, for the grain is ready: come, get you down, for the wine-crusher is full, the vessels are overflowing; for great is their evil-doing. 19 Masses on masses in the valley of decision! for the day of the Lord is near in the valley of decision. 20 The sun and the moon have become dark, and the stars keep back their shining. 21 And the Lord will be thundering from Zion, and his voice will be sounding from Jerusalem; and the heavens and the earth will be shaking: but the Lord will be a breastplate for his people and a strong place for the children of Israel.

Matthew Henry's Commentary on Joel 3:17-21

Commentary on Joel 3:9-17

(Read Joel 3:9-17)

Here is a challenge to all the enemies of God's people. There is no escaping God's judgments; hardened sinners, in that day of wrath, shall be cut off from all comfort and joy. Most of the prophets foretell the same final victory of the church of God over all that oppose it. To the wicked it will be a terrible day, but to the righteous it will be a joyful day. What cause have those who possess an interest in Christ, to glory in their Strength and their Redeemer! The acceptable year of the Lord, a day of such great favour to some, will be a day of remarkable vengeance to others: let every one that is out of Christ awake, and flee from the wrath to come.

Commentary on Joel 3:18-21

(Read Joel 3:18-21)

There shall be abundant Divine influences, and the gospel will spread speedily into the remotest corners of the earth. These events are predicted under significant emblems; there is a day coming, when every thing amiss shall be amended. The fountain of this plenty is in the house of God, whence the streams take rise. Christ is this Fountain; his sufferings, merit, and grace, cleanse, refresh, and make fruitful. Gospel grace, flowing from Christ, shall reach to the Gentile world, to the most remote regions, and make them abound in fruits of righteousness; and from the house of the Lord above, from his heavenly temple, flows all the good we daily taste, and hope to enjoy eternally.