Matthew Henry Commentary Joel 3:18-21

"And it shall come to pass in that day, that the mountains shall drop down sweet wine, and the hills shall flow with milk, and all the brooks of Judah shall flow with waters; and a fountain shall come forth from the house of Jehovah, and shall water the valley of Shittim. Egypt shall be a desolation, and Edom shall be a desolate wilderness, for the violence done to the children of Judah, because they have shed innocent blood in their land. But Judah shall abide for ever, and Jerusalem from generation to generation. And I will cleanse their blood, that I have not cleansed: for Jehovah dwelleth in Zion." — Joel 3:18-21 (ASV)

There will be abundant Divine influences, and the gospel will spread speedily into the remotest corners of the earth. These events are predicted under significant emblems; a day is coming when everything that is amiss will be amended.

The fountain of this plenty is in the house of God, from which the streams originate. Christ is this Fountain; his sufferings, merit, and grace cleanse, refresh, and make fruitful.

Gospel grace, flowing from Christ, will reach the Gentile world, to the most remote regions, and make them abound in fruits of righteousness. From the house of the Lord above, from his heavenly temple, flows all the good we daily taste and hope to enjoy eternally.