Gaebelein's Annotated Bible
And the LORD said unto Moses, See, I have made thee a god to Pharaoh: and Aaron thy brother shall be thy prophet.
And the LORD said unto Moses, Pharaoh's heart is hardened, he refuseth to let the people go.4. The Nine Plagues and the Tenth Judgment Announced
CHAPTER 7:14-25 The First Plague
1. The plague announced (Exodus 7:14-19)
2. The judgment executed (Exodus 7:20-25)
Nine judgment plagues follow, and after they had passed, the tenth, the great judgment, fell upon Egypt. There are striking and different characteristics of these plagues. Aaron uses his rod in the beginning of the plagues, while Moses stretches out his rod and hand in the last three, not counting the slaying of the firstborn. Some of them were announced beforehand, others were not announced and came without warning. We give them now in their order:
1. Water turned into blood;
9. Darkness (see Psalm 105:26-36).
The process of the hardening of Pharaoh’s heart progresses with these judgments till God hardened him completely. After the first plague his heart was hardened (or firm) and deliberately he set himself to do this. Note this process in Exodus 8:15; Exodus 8:19; Exodus 8:31; and Exodus 9:7. When this present age closes with the great tribulation and the vials of God’s wrath are poured out upon an unbelieving world, the hearts of the earthdwellers and Christ rejectors will be hardened and thus ripe for the day of wrath. The book of Revelation acquaints us with this solemn fact.
“The plagues of Egypt are founded on the natural features which Egypt presents, so that they are unprecedented and extraordinary, not so much in themselves, as on account of their power and extent, and their rapid succession when Moses simply gives the command. As they are, consequently, both natural and supernatural, they afford both to faith and to unbelief the freedom to choose (in Pharaoh, unbelief prevailed); they are, besides, adapted to convince the Egyptians that Jehovah is not merely the national God of the Israelites, but a God above all gods, who holds in his hand all the powers of nature likewise, which Egypt was accustomed to deify” (J.H. Kurtz).
The water of the river Nile was turned into blood. The Nile was worshipped by the Egyptians and now this great river was polluted. Strange that even orthodox commentators can state that the change in the water was a change in color produced by red earth or by a certain water plant. But we know a real change took place, for the water stank and the fish died. Thus the Nile , known as Osiris, became an object of abomination and death. The messengers of Satan imitated this miracle also. This plague lasted seven days.