He cutteth out rivers among the rocks. Some understand this of man's general ability to cut canals and tunnels, and change the course of rivers. But the allusion is more probably to the works undertaken in mines for the carrying off of the water from them.
Diodorus says that when subterranean springs were tapped in mines, which threatened to flood them, it was usual to construct ducts, or tunnels, by which the inconvenient liquid might be carried off to a lower level (Diod.
Siculus, 5.37. § 3). And his eye seeth every precious thing. Nothing escapes his notice. Even as he constructs these duets he has his eye open to note any signs of mineral wealth, of metals or of precious stones, that occur along the line of his excavation.