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,^[1] as consecrated minister of the great and holy tabernacle, which the Lord has erected and not man.^[2]

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?

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.

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.^[1]

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,^[1] 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.^[2] 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.

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.

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.

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.^[1] 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,^[2] 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.^[3]

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.

Just as we read in the Gospel that water was turned into wine,^[1] 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.

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.

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,^[1] and it warns us what is to be understood even when it is not expressed.

For what reason do you puff yourself up with human pride? A man insulted you, and you swelled up and were angered. Rid yourself of the fleas that you may sleep. Find out who you are! For that you may know, brothers, that these things which would bother us were created to enable us to control our pride, [remember], God could have tamed the proud people of Phar-aoh with bears, with lions or with snakes; he sent flies and frogs upon them that their pride might be tamed by the most ignoble of things.

In the second plague frogs are brought forth. They are thought to stand figuratively for the songs of the poets. The poets have brought deceptive fables into this world, with their empty and conceited songs that are like the croaking of frogs. For the frog stands for empty loquacity. That animal is good for nothing else but to give out the sounds of its voice in offensive and annoying noises.

One should also observe that the term prayer, which often differs in meaning from invocation, is here employed in the case of one who promises in a vow to do certain things if God grants him certain other things. But the term is also used in the ordinary way. For example, we found this to be so in Exodus after the description of the plague of the frogs, which was the second of the ten plagues: . . . But Pharaoh called Moses and Aaron and said to them: ‘Pray to the Lord on my account to take away the frogs from me and my people; and I will let the people go to sacrifice to the Lord.’ When Pharaoh employs the word prayer the habitual meaning of prayer is conveyed in addition to the above meaning. If anyone finds this difficult to see, it becomes clear in what follows, namely: And Moses said to Pharaoh: ‘Set me a time when I shall pray for you, and for your servants, and for your people, that the frogs may be driven away from you and from your house and from your people, and may remain only in the river.’

We noted, however, that in the case of the sciniphs,^[1] the third plague, Pharaoh does not ask that prayer be made, nor does Moses pray. And in the case of the flies, the fourth plague, he says, Pray therefore for me to the Lord. And then Moses said, I will go out from you and will pray to the Lord. And the flies shall depart from Pharaoh, and from his servants, and from his people tomorrow.^[2] And a little further on we read: So Moses went out from Pharaoh and prayed to God.^[3] Again in the case of the fifth and also of the sixth plague Pharaoh did not ask that prayer be made, nor did Moses pray. In the seventh plague Pharaoh sent and called Moses and Aaron, saying to them, ‘I have sinned this time. The Lord is just, but I and my people are wicked. Pray to the Lord, that the thunderings of God and the hail and the fire may cease.’^[4] And a little further on we read: And Moses went from Pharaoh out of the city and stretched forth his hands to the Lord; and the thunders . . . ceased.^[5] We shall discuss more suitably at another time why it is not said as on the previous occasions that he prayed but rather that he stretched forth his hands to the Lord. And in the case of the eighth plague Pharaoh says, And pray to the Lord your God, that he take away from me this death. And Moses going forth from the presence of Pharaoh, prayed to the Lord.^[6]

Take the example of Pharaoh, a man given to vain, empty thoughts. His land of Egypt was afflicted with a plague of frogs. They gave forth a surfeit of sound, meaningless and senseless. Moses said to Pharaoh, Set me a time when I shall pray for you and for your servants and for your people that the Lord may exterminate the frogs.^[1] Pharaoh, who because of his plight should have besought him to offer prayer, replied, Tomorrow, thus showing himself indifferent to the punishment that the delay would bring, although he was still intent on saving Egypt from the plague. And so, when his prayer was finally granted, he was unmindful of gratitude. Being puffed up in heart, he forgot God.