John Calvin Commentary Psalms 107:33

"He turneth rivers into a wilderness, And watersprings into a thirsty ground;" — Psalms 107:33 (ASV)

He turneth rivers into a wilderness. Here then is an account of changes which it would be the height of folly to attribute to chance. Fruitful lands become unfruitful, and barren lands assume the new aspect of freshness and fruitfulness.

And how does it happen that one district becomes sterile, and another becomes rich and fertile, contrary to what they used to be, except because God pours out his wrath upon the inhabitants of the one, by taking his blessing from them, and makes the other fruitful to feed the hungry?

It may be ascribed to the sparseness of the population that many parts of Asia and Greece, once exceedingly fruitful, now lie uncultivated and unproductive. However, we must attribute to the providence of God, which the prophet praises, the well-authenticated fact that in some places the earth that was fruitful has now become barren and parched, while others are beginning to be fertile.

However, it is not sufficient merely to observe that these wonderful revolutions of the earth's surface are the result of God’s overruling purpose, unless we also observe, secondly, what the prophet does not omit: that the earth is cursed by him on account of the iniquity of its inhabitants, who prove themselves undeserving of being so amply sustained by his bountiful hand. He has put pools and springs of water for fields or countries where there is an abundance of water, because moisture is required to nourish the plants by which fruit is produced. The term saltness is used metaphorically, since there is nothing more sterile than salt; hence that saying of Christ’s, If the salt have lost its saltness, what further purpose will it serve? (Mark 9:50)—indeed, not even for barrenness.

Consequently, when men intended to doom any place to remain unproductive, they usually sowed it with salt. And it is probably in allusion to this ancient custom that the prophet says the land was covered with salt.