19. And the Lord spake unto Moses. This is the more extended narrative of which I spoke; for Moses mentions nothing different from what went before, but explains more distinctly his mode of action in the performance of the miracle, namely, that what God had commanded was completed by the instrumentality of Aaron. There was a reason for commencing with this miracle, that the Egyptians might know that there was no safeguard for them in the resources upon which they prided themselves the most. We know what great wealth, defense, and conveniences arose to them from the Nile; thence came their abundant fisheries, thence the fertility of their whole country, which it irrigated in its inundation, a thing that, in other lands is injurious; its navigation was most advantageous for their merchants, it was also a strong fortification to a good part of the kingdom. Therefore, in order to cast down the Egyptians from their principal dependence, He turns its waters into blood. Besides, because water is one of the two elements of which man’s life consists, in depriving the Egyptians of one part of their life, He used the best and shortest method of humiliating their haughtiness, had they not been altogether intractable. He might, indeed, by a single breath, have dried up all the sources of water, and overwhelmed the whole nation by drought; but this would have been commonly believed to have happened by chance, or naturally, and therefore would have been a less apparent prodigy, whilst it would have shut up the way for others. It would, then, have been sufficient, by the terror of death it awakened, to turn them to the fear of God, unless their madness had been desperate. Moses enumerates, besides the river, the streams, and ponds, and pools of water; because, in different parts of the country, as well artificially as naturally, the Nile was so diffused, that scarcely any other country is provided in all directions with such an abundance of water; as though God should say, “It shall avail you nothing to possess such an immense supply of water; because you shall thirst as much as if the Nile were dry.” He adds, “both in vessels of wood and in vessels of stone;” meaning, that in whatever kind of vessel they came to draw, they would find nothing but blood.