1 And the LORD said unto Moses, See, I have made thee a god to Pharaoh: and Aaron thy brother shall be thy prophet. 2 Thou shalt speak all that I command thee: and Aaron thy brother shall speak unto Pharaoh, that he send the children of Israel out of his land. 3 And I will harden Pharaoh's heart, and multiply my signs and my wonders in the land of Egypt. 4 But Pharaoh shall not hearken unto you, that I may lay my hand upon Egypt, and bring forth mine armies, and my people the children of Israel, out of the land of Egypt by great judgments. 5 And the Egyptians shall know that I am the LORD, when I stretch forth mine hand upon Egypt, and bring out the children of Israel from among them. 6 And Moses and Aaron did as the LORD commanded them, so did they. 7 And Moses was fourscore years old, and Aaron fourscore and three years old, when they spake unto Pharaoh. 8 And the LORD spake unto Moses and unto Aaron, saying, 9 When Pharaoh shall speak unto you, saying, Shew a miracle for you: then thou shalt say unto Aaron, Take thy rod, and cast it before Pharaoh, and it shall become a serpent. 10 And Moses and Aaron went in unto Pharaoh, and they did so as the LORD had commanded: and Aaron cast down his rod before Pharaoh, and before his servants, and it became a serpent. 11 Then Pharaoh also called the wise men and the sorcerers: now the magicians of Egypt, they also did in like manner with their enchantments. 12 For they cast down every man his rod, and they became serpents: but Aaron's rod swallowed up their rods. 13 And he hardened Pharaoh's heart, that he hearkened not unto them; as the LORD had said. 14 And the LORD said unto Moses, Pharaoh's heart is hardened, he refuseth to let the people go. 15 Get thee unto Pharaoh in the morning; lo, he goeth out unto the water; and thou shalt stand by the river's brink against he come; and the rod which was turned to a serpent shalt thou take in thine hand. 16 And thou shalt say unto him, The LORD God of the Hebrews hath sent me unto thee, saying, Let my people go, that they may serve me in the wilderness: and, behold, hitherto thou wouldest not hear. 17 Thus saith the LORD, In this thou shalt know that I am the LORD: behold, I will smite with the rod that is in mine hand upon the waters which are in the river, and they shall be turned to blood. 18 And the fish that is in the river shall die, and the river shall stink; and the Egyptians shall lothe to drink of the water of the river. 19 And the LORD spake unto Moses, Say unto Aaron, Take thy rod, and stretch out thine hand upon the waters of Egypt, upon their streams, upon their rivers, and upon their ponds, and upon all their pools of water, that they may become blood; and that there may be blood throughout all the land of Egypt, both in vessels of wood, and in vessels of stone. 20 And Moses and Aaron did so, as the LORD commanded; and he lifted up the rod, and smote the waters that were in the river, in the sight of Pharaoh, and in the sight of his servants; and all the waters that were in the river were turned to blood. 21 And the fish that was in the river died; and the river stank, and the Egyptians could not drink of the water of the river; and there was blood throughout all the land of Egypt. 22 And the magicians of Egypt did so with their enchantments: and Pharaoh's heart was hardened, neither did he hearken unto them; as the LORD had said. 23 And Pharaoh turned and went into his house, neither did he set his heart to this also. 24 And all the Egyptians digged round about the river for water to drink; for they could not drink of the water of the river. 25 And seven days were fulfilled, after that the LORD had smitten the river.
[AD 258] Novatian on Exodus 7:1
Why in the world, after reading that this name was also given to Moses, when it is stated, “I have made you as god to Pharaoh,” should they deny this title to Christ who we find has been constituted not a god to Pharaoh but rather the Lord and God of all creation?

[AD 379] Basil of Caesarea on Exodus 7:1
Moses was appointed god of the Egyptians when he who was giving the revelation spoke to him in this manner: “I have appointed you the god of Pharaoh.” Therefore the title conveys an indication of some power, either protective or active. But the divine nature in all the names which may be contrived remains, just as it is, inexplicable, as is our teaching.

[AD 390] Gregory of Nazianzus on Exodus 7:1
So Moses was a god to Pharaoh, but a servant of God, as it is written. The stars which illumine the night are hidden by the sun, so much that you could not even know of their existence by daylight. A little torch brought near a great blaze is neither destroyed nor seen nor extinguished; but it is all one blaze, the bigger one prevailing over the other.

[AD 397] Ambrose of Milan on Exodus 7:1
He so far exceeded the dignity of his human state that he was given the title of “god” as we read in the Scriptures, where the Lord speaks: “I have appointed you the god of Pharaoh.” He was in fact victorious over all his passions and was not allured by the enticements of the world. He enveloped this our habitation here in the body with a purity that savored of a “citizenship that is in heaven.” By directing his mind and by subduing and castigating his flesh with an authority that was almost regal, he was given the name of “god,” by whom he had modeled his life through numerous acts of perfect virtue.

[AD 397] Ambrose of Milan on Exodus 7:1
But if they think [Christ] is called God because he had an in-dwelling of the Godhead within him, as many holy men were (for the Scripture calls them gods to whom the word of God came)—they do not place him before other men but think he is to be compared with them. They consider him to be the same as he granted other men to be, even as he says to Moses: “I have made you a god unto Pharaoh.” Similarly it is also said in the psalms: “I have said, you are gods.”

[AD 420] Jerome on Exodus 7:1
“I said: You are gods, all of you sons of the Most High.” Let Eunomius hear this, let Arius, who says that the Son of God is son in the same way that we are. That we are gods is not so by nature but by grace. “But to as many as received him he gave the power of becoming sons of God.” I made man for that purpose, that from men they may become gods. “I said: You are gods, all of you sons of the Most High.” Imagine the grandeur of our dignity; we are called gods and sons! I have made you gods just as I made Moses a god to Pharaoh, so that after you are gods, you may be made worthy to be sons of God. Reflect upon the divine words: “With God there is no respect of persons.” God did not say, “I said, you are gods, you kings and princes”; but “all” to whom I have given equally a body, a soul and a spirit, I have given equally divinity and adoption. We are all born equal, emperors and paupers; and we die as equals. Our humanity is of one quality.

[AD 450] Peter Chrysologus on Exodus 7:1
Hence it is that through the influence of these three things Moses is made a god: for the sake of his military triumphs he brings all the elements under his control. He bids the sea to withdraw, its waves to solidify, its bottom to become dry and the sky to drop its rain. He supplies food, compels the winds to scatter meats, illumines the night with the splendor of the sun, tempers the sun by the veil of the cloud. He strikes the rock to make it yield from its fresh wound cool streams of water for those who thirst. He first gives to the earth heaven’s law, writes down the norms of living, sets the terms of disciplinary control.

[AD 749] John Damascene on Exodus 7:1
I say that they are gods, lords and kings not by nature but because they have ruled over and dominated sufferings and because they have kept undebased the likeness of the divine image to which they were made—for the image of the king is also called a king. Finally … they have freely been united to God and [by] receiving him as a dweller within themselves have through association with him become by grace what he is by nature.

[AD 1781] Richard Challoner on Exodus 7:1
The god of Pharao: Viz., to be his judge; and to exercise a divine power, as God's instrument, over him and his people.
[AD 430] Augustine of Hippo on Exodus 7:3
God constantly says, “I will harden Pharaoh’s heart,” and gives the reason why he does this. He says, “I will harden Pharaoh’s heart and fulfill my signs and my portents in Egypt,” as if the hardening of Pharaoh’s heart were necessary so that God’s signs might be multiplied and fulfilled in Egypt. God makes good use of bad hearts for what he wishes to show to those who are good or those he is going to make good. And the quality of evil in each heart (that is, what sort of heart is disposed to evil) came about through its own evildoing, which grew from the choice of the will. Still, those evils in quality, so that the heart is moved this way or that, when it is moved to evil this way or that way, comes to be by causes by which the soul is driven. And whether these causes either exist or do not exist is not within the power of man. They come from the providence of God that is hidden, most just and clearly most wise, who disposes and administers the universe that he created. So that Pharaoh had such a heart, which was not moved by God’s patience to piety but rather to impiety, was the result of his own vice. But that those things happened by which his heart, so evil by its own vice, resisted God’s command—it is called “hardened” because it did not bend and agree but resisted unbendingly—was of divine dispensation. It was not unjust to such a heart. It was clearly a just punishment [that] was being prepared, by which those who feared God would be corrected. For example: when money is offered for the commission of homicide, a greedy man is moved in one way, but one who disdains money is moved in another way. The former is moved to commit the crime, the latter to being cautious. Yet the offer of the money itself was not under the control of either of them. Thus motives come to evil men that indeed are not under their control, but they act from these motives as they find them already established from their own past willing. We should consider whether the phrase can be understood in this way: “I shall harden,” as if he were saying, “I shall show how hard his heart is.”

[AD 1781] Richard Challoner on Exodus 7:3
I shall harden: not by being the efficient cause of his hardness of heart, but by permitting it; and by withdrawing grace from him, in punishment of his malice; which alone was the proper cause of his being hardened.
[AD 215] Clement of Alexandria on Exodus 7:7
On the same basis, you would not be able to point to anyone of the past generations approaching a pregnant woman in the pages of Scripture. Only later, after the birth and weaning of the child, would you again find the wives in physical relations with their husbands. You will find that Moses’ father observed this point. He left a three-year gap after Aaron’s birth before fathering Moses.

[AD 390] Gregory of Nazianzus on Exodus 7:8-9
Great indeed was Moses, who afflicted Egypt grievously and saved his people by many signs and prodigies, who went within the cloud and instituted the twofold law: the law of the letter without and the law of the spirit within. Aaron also, the brother of Moses according to the flesh and the spirit, sacrificed and prayed on behalf of the people, as consecrated minister of the great and holy tabernacle, “which the Lord has erected and not man.”

[AD 430] Augustine of Hippo on Exodus 7:8-9
Here indeed there was no need to use the service of the voice, for which Aaron was provided out of necessity, on account of the weakness of Moses’ voice. But the staff was to be cast down so that it would become a serpent. Why did Moses himself not do this, except because that mediation of Aaron himself between Moses and Pharaoh was the symbol of some great matter?

[AD 373] Ephrem the Syrian on Exodus 7:10
The staff is a sign of the cross. It caused all the plagues when it swallowed the snakes, just as [the cross] would destroy all idols. With [the staff], [Moses] divided the sea and drowned the Egyptians. That prefigured the destruction of the Canaanites.

[AD 397] Ambrose of Milan on Exodus 7:10
He cast down his rod, and it became a serpent which devoured the serpents of Egypt. This signified that the Word should become flesh to destroy the poison of the dread serpent by the forgiveness and pardon of sins. For the rod stands for the Word that is true, royal, filled with power and glorious in ruling. As the rod became a serpent, so he who was the Son of God begotten of the Father became the Son of man born of a woman. Like the serpent, he was lifted up on the cross, poured his healing medicine on the wounds of humanity. Wherefore the Lord himself says, “As Moses lifted up the serpent in the wilderness, so must the Son of Man be lifted up.”

[AD 430] Augustine of Hippo on Exodus 7:10
For by the serpent is to be understood death, which was brought about by the serpent in paradise, according to the manner of speech which attributes the effect to the cause. Therefore the rod was turned into a serpent, and the whole Christ, together with his body which is the church, into the resurrection, that will take place at the end of time. This is signified by the tail of the serpent which Moses held, in order that it might be turned again into a rod. But the serpents of the magicians are like those who are dead in the world, for, unless by believing in Christ they have been as it were swallowed up and entered into his body, they will not be able to rise in him.

[AD 430] Augustine of Hippo on Exodus 7:11
We read that the magicians of the Egyptians were very skilled in those arts, but they were outdone by Moses, the servant of God. Yet when they performed certain wonders by their forbidden arts, he overturned all their trickery by simply calling on God.

[AD 430] Augustine of Hippo on Exodus 7:11
The magicians of Pharaoh, the king of Egypt who was tyrannizing over this people, were permitted to accomplish certain wonders merely that they might be outdone by more genuine miracles. These magicians worked by the kind of sorceries and incantations to which evil spirits or demons are addicted, while Moses was powerful by his holiness and helped by the angels, and so, in the name of God, creator of heaven and earth, he easily triumphed over them.

[AD 430] Augustine of Hippo on Exodus 7:11
Consequently it happens that the holy servants of God, when it is useful for them to have this gift, in accord, the power of the most high God, have command over the lowest powers in order to perform certain visible miracles. This power thus becomes publicly known, as if it were imperial law. For it is God himself who rules in them, whose temple they are, and whom they, having despised their own private power, love most fervently. However, in magical imprecation, in order to make the deception attractive so as to subjugate to themselves those [magicians] to whom they grant such things, [the lowest powers] give effect to their prayers and rituals, and they dispense through that private law what they are allowed to dispense to those who honor them and serve them and keep certain covenants with them in their mystery rites. And when the magicians appear to have command, they frighten their inferiors with the names of more elevated [powers] and exhibit to those looking on with wonder some visible effects. Due to the weakness of the flesh, these seem momentous to those unable to behold eternal things, which the true God offers through himself to those who love him. However, God permits these things through his righteous government of all things, in order that he may distribute to them the kinds of bondage or the kinds of freedom that are proportioned to their own desires and choices. And if they gain something for their own evil desires when they call upon the most high God, that is a punishment and not a kindness. Indeed not without reason does the apostle say, “God has given them over to the desires of their hearts.” For the opportunity to commit certain sins is a punishment for other preceding sins.…But as for the Lord’s claim that false prophets will perform many signs and wonders so as to deceive, if possible, even the elect, clearly he is urging us to understand that even wicked men do certain miracles of a kind which the saints cannot do. Still, they must not be thought to be in a better position with God on that account, for the magicians of the Egyptians were not more acceptable to God than were the Israelite people because the latter could not do what the magicians were doing, although Moses had been able to do greater things by the power of God. However, the reason for not granting these miracles to all the saints is this: to prevent the weak from being deceived by a most pernicious error of supposing that there are greater gifts in such feats than in the works of righteousness whereby one obtains eternal life. Accordingly the Lord prohibits his disciples from rejoicing on this account when he says, “Do not rejoice in this, that the spirits are subject to you; rather, rejoice in this, that your names are written in heaven.”15
When therefore magicians do things of a kind which the saints sometimes do, remember that their deeds appear to the eye to be alike, but they are done both for a different purpose and under a different law. For the former act seeking their own glory; the latter, the glory of God. Again, the former act through certain things granted to the powers in their own sphere, as if through business arrangements and magic arts of a private nature; but the latter, by a public administration at the command of him to whom the entire creation is subject. For it is one thing for an owner to be compelled to give his horse to a soldier; it is another thing for him to hand it over to a buyer or to give or lend it to someone. And just as a great many evil soldiers, whom imperial discipline condemns, terrify some owners with the ensigns of their commander and extort from them something which is not in accord with public law, so evil Christians or schismatics or heretics sometimes exact through the name of Christ or Christian words or sacraments something from the powers who have been enjoined to defer to the honor of Christ. However, when the powers submit to the bidding of evil men, they do so willingly in order to seduce others, in whose error they rejoice. Consequently it is one thing for magicians to perform miracles, another for good Christians, and another for evil Christians. Magicians do so through private contracts, good Christians through a public righteousness, and evil Christians through the “ensigns” or symbols of this public righteousness.

[AD 1781] Richard Challoner on Exodus 7:11
Magicians: Jannes, and Mambres, or Jambres, 2 Tim. 3. 8.
[AD 585] Cassiodorus on Exodus 7:20
Just as we read in the Gospel that water was turned into wine, which denoted that people were changed for the better, so here its transformation into blood announces that sinners interpret the causes of spiritual things in a bodily sense. Blood is introduced here to denote the flesh, and undoubtedly the Jewish people took this materialistic view. He further says that both their rivers and their rain showers were turned into blood, so that in their preoccupation with the thoughts of the flesh they did not understand the heavenly preaching in a spiritual sense. The literal sense of this and of what follows is clear, for the words of the divine history show that these events occurred in Egypt.

[AD 636] Isidore of Seville on Exodus 7:20
Then the plagues are visited upon Egypt. They were carried out corporally among the Egyptians; they are now carried out spiritually in us, for Egypt is the figure of this world. The first plague is the one in which the waters are turned into blood. The waters of Egypt are erratic, just as the dogmas of the philosophers are inconstant. These waters are deservedly turned into blood, because when the philosophers ponder the causes of things they think carnally. But when the cross of Christ shows the light of truth to this world, it will reproach the world with censures of this sort, so that from the kind of punishment it suffers, the world might recognize its errors.

[AD 430] Augustine of Hippo on Exodus 7:24
You asked … how, when all the water of Egypt was turned into blood, the magicians of Pharaoh found any [water] with which they could transform in like manner. This difficulty is usually solved in two ways. They did it either because some sea water could be brought or, what is more likely, because in that part of the country where the children of Israel were those plagues did not take place. In certain passages of that Scripture this is very clearly expressed, and it warns us what is to be understood even when it is not expressed.