Book of Joel Chapter 3 Vs. 18

The Glorious Future of Judah 

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. Joel 3:18

And it shall... At that time (in that day, when Messiah will reign over His people in the Millennium) the land will be a virtual paradise, enabling the Lord’s people to enjoy His agricultural blessings to the fullest.

that the mountains... The grape harvest will be so bountiful that wine will seemingly drip from the mountains. Milk will be just as plentiful. It too was a sign of prosperity; Canaan was described as a land “flowing with milk and honey” (see Exo. 3:8; cf. 13:5; 33:3; Lev. 20:24; also Isa. 55:1).

and all the... The seasonal streams (ravines, or wadis) will no longer run dry. This abundance of wine, milk (implying the existence of extensive herds), and water represents a complete reversal of the effects of the locust plague (cf. Joel 1:5, 1:18, 1:20).

and a fountain... This refers to the source of the great river of. A fountain will flow out of the Lord’s house, the Jerusalem temple. Similar imagery is employed in Eze. 47:1-12 and Zec. 14:8. This fountain (and the river it produces) will be a tangible reminder that the Lord is the Source of the land’s fertility (cf. Eze. 47:8-10, 47:12).

and shall water... The valley of acacias (Shittim) is probably that portion of the Kidron Valley which runs through the arid wilderness to the Dead Sea (cf. Eze. 47:8).

At that time (in that day, when Messiah will reign over His people in the Millennium) the land will be a virtual paradise, enabling the Lord’s people to enjoy His agricultural blessings to the fullest. The grape harvest will be so bountiful that wine will seemingly drip from the mountains. Milk will be just as plentiful. It too was a sign of prosperity; Canaan was described as a land “flowing with milk and honey” (see Exo. 3:8; cf. 13:5; 33:3; Lev. 20:24; also note Isa. 55:1). The seasonal streams (ravines, or wadis) will no longer run dry. This abundance of wine, milk (implying the existence of extensive herds), and water represents a complete reversal of the effects of the locust plague (cf. Joel 1:5, 1:18, 1:20).