Matthew Poole and continuators on Isaiah 41:18

18. I will open rivers in high places , and fountains in the midst of the Valleys : I will make the wilderness a pool of water, and the dry land springs of water .

Upon the Mountains where by the course of nature there are no Rivers.

Or, in the Vallies, to wit, in such of them as are not well watered.

These people who were like a dry and barren Wilderness, I will abundantly water with my Blessing, and make them fruitful and beuatiful, as the next verse sheweth: which may be understood, either of the Iews who were in a Wilderness condition, till God brought them out of it; Or, of the Gentiles converted to the true Religion under the Gospel.

Marginal references: Chap. 30. 25 & 35. 7. & 44. 3.; Psal. 107. 35.