Then the Lord, &c.— The Lord here, as usual, denounces the threat, appoints the exact time of its execution, and, fully to demonstrate his immediate power and distinguishing mercy, declares that Israel, his people, should be exempt from it, while Egypt should feel the stroke, though their cattle, &c. were intermixed, breathed the same air, and ate the same food; Exodus 9:4-5. Owen observes here, that the air, as well as the water and the land, was another of the chief divinities of the Egyptians; to whom they attributed the salubrity of the climate, and the healthiness of their own constitutions; and whose benevolence, therefore, they studied to engage, by the offerings of daily incense. To convince them of the falsity of this notion; to shew them, "that God alone woundeth and healeth, killeth and maketh alive;" he changed the qualities of the air, and rendered it pestilential, exciting inflamed tumors, and virulent ulcers, in man and beast throughout all the land of Egypt.
Then again: as they ascribed the exuberance, growth, and maturity of all vegetable productions, to the influences of this divinity, the air; so the Lord strengthened that element to reprove their error, and caused it to produce such dreadful storms of rain, hail, thunder, and lightning, as had never been known since the foundation of Egypt as a kingdom; whereby the greatest part of the herbage and fruit was blasted and destroyed. And afterwards the east-wind, which they likewise adored, conveyed a large flight of locusts to devour the remainder.