What does 2 Kings 3:18 mean?

But now bring me a musician.” When the musician played, Yahweh’s hand came on him.

He said, “Yahweh says, ‘Make this valley full of trenches.’

For Yahweh says, ‘You will not see wind, neither will you see rain, yet that valley will be filled with water, and you will drink, both you and your livestock and your other animals.

You shall strike every fortified city, and every choice city, and shall fell every good tree, and stop all springs of water, and mar every good piece of land with stones.’”

In the morning, about the time of offering the sacrifice, behold, water came by the way of Edom, and the country was filled with water.

Now when all the Moabites heard that the kings had come up to fight against them, they gathered themselves together, all who were able to put on armor, young and old, and stood on the border.