He turneth rivers into a wilderness - He makes great changes in the earth; he shows that he has absolute dominion over it. See the notes at Isaiah 44:26-27. On the word “wilderness,” see the notes at Psalms 107:4. The point here is, that God had such control over nature that he could make the bed of a river dry and barren as the rocky or sandy desert. He could effectually dry up the stream, and make it so dry and parched that nothing would grow but the most stunted shrubs, such as were found in the waste and sandy desert.
And the water-springs into dry ground - The very fountains of the rivers: not only drying up the river itself by leading it off into burning wastes where it would be evaporated by the heat, or lost in the sand - but so directly affecting the “sources” of the streams as to make them dry.