And it shall come to pass in that day, that the mountains shall drop down new wine, and the hills shall flow with milk, and all the rivers of Judah shall flow with waters, and a fountain shall come forth of the house of the LORD, and shall water the valley of Shittim.
The mountains shall drop down new wine - figurative for abundance of vines, which were cultivated in terraces of earth between the rocks on the sides of the hills of Palestine (Amos 9:13, "The mountains," instead of mist or vapour, shall distill that which maketh glad the heart of man, new wine, Psalms 104:15).
And the hills shall flow with milk - i:e., they shall abound in flocks and herds yielding milk plentifully, through the richness of the pastures.
And all the rivers of Judah shall flow with waters - the great desideratum for fertility in the parched East (Isaiah 30:25).
And a fountain shall come forth of the house of the Lord, and shall water the valley of Shittim - the blessings, temporal and spiritual, issuing from Yahweh's house at Jerusalem, shall extend even to Shittim, on the border between Moab and Israel, beyond Jordan (Numbers 25:1; Numbers 33:49; Joshua 2:1; Micah 6:5). Shittim means acacias, which grow only in arid regions: implying that even the arid desert shall be fertilized by the blessing from Jerusalem. So Ezekiel 47:1-12 describes the waters issuing from the threshold of the house as flowing into the Dead Sea, and purifying it. Also in Zechariah 14:8 ("Living waters shall go out from Jerusalem; half of them toward the former sea, and half of them toward the hinder sea: in summer and in winter shall it be") the waters flow on one side into the Mediterranean, on the other side into the Dead Sea, near which latter Shittim was situated (cf. Psalms 46:4, "There is a river the streams whereof shall make glad the city of God." So in the final heavenly Jerusalem, Revelation 22:1). The fact in nature which suggested the image was, that there was a fountain under the temple which carried off the blood of the sacrifices; and carrying it off, was intermingled with that blood, the image of the all-atoning blood of Christ. Zechariah adds to Joel's image the idea of the perennial permanence of the life-giving, stream, "in summer and in winter shall it be" (Zechariah 14:8). Ezekiel adds the ideas of the gradual increase of the waters of life, their exceeding depth, the healing of all which could be healed, and the abiding desolation wherever the waters did not reach (Pusey).