Exodus 7:17

Thou shalt know. At a previous visit Pharaoh had declared, “I know not the Lord” (Exodus 5:2). Moses now warns the rash monarch that he will soon be given an opportunity to learn something of the power of God (see Exodus 9:14). The Nile god, the source of fertility and blessing, was to become an agent of death.

The plagues visited upon the Egyptians were designed not only to bring Pharaoh and his people to a recognition of the true God but also to destroy confidence in the power and protection of their false gods (Exodus 12:12). Each of the ten plagues was painfully literal, and yet at the same time was directed against some phase of false religion. In the merciful providence of God, physical suffering occasioned by each plague was to lead the king and his counselors to reconsider their ways, that they might learn the folly of serving idols and the wisdom of cooperating with the God of heaven. In ancient Egypt the interests of king and priest were closely related, the king himself always being initiated into the priestly caste. Pharaoh and the priests rightly surmised that the stability of both church and state was at stake. The people and the counselors of the king, from more practical considerations, were ready to submit long in advance of the king and the priests (Exodus 10:7). It was only following the tenth plague, as a result of which the next generation of royalty and of the priesthood died, that the latter were, for the moment, ready to submit (Patriarchs and Prophets, pp. 272, 283). In the plagues that fell upon Egypt we behold a preview of the more terrible and extensive judgments of God soon to fall upon the earth (Great Controversy, pp. 269, 627).

Turned to blood. These words do not imply that the Nile waters would merely take on the color of blood, as some commentators have interpreted this passage, but rather that they would to all intents and purposes, actually become blood. It is beside the point to ask whether the water would have passed the various modern tests, microscopic and others, by which blood is analyzed. The water appeared to be blood, and was taken to be blood.

It was not merely water discolored by red soil from Abyssinia. Some have suggested as a possible cause a high concentration of “cryptogamic plants and infusoria,” something similar to the “red tide” of microscopic organisms that kills millions of fish and brings a stench and an irritating gas to shores, bays, and inlets. It can be questioned whether water thus altered could fill all the specifications of this Biblical plague. Certainly the timing could not be controlled by man.