Midrash sa Exodo 8:13: Midrash Tanchuma, Midrash Tanchuma Buber, Shemot Rabbah & Pirkei DeRabbi Eliezer

Our sages of blessed memory said: The Holy One, blessed be He, followed the military tactics employed by kings when inflicting the plagues upon them. When the people of a province rebel, a human king dispatches his legions to surround them. First he dams up their water supply. If the people repent, well and good; but if not, he orders thunderous noises to be directed against them. If they are contrite, good; but if not, he commands that arrows be shot at them. If they relent (their actions), well and good; but if not, he sends barbarians against them. If they retract, good; but if not, he orders other reprisals to be taken against them. If they are contrite, well and good; but if not, he orders naphtha to be hurled upon them. If they are repentant, good; but if not, he catapults stones upon them. If they repent, good; but if not, he turns a large population against them. If they retract, good; but if not, he imprisons them. If they relent, good; but if not, he destroys their leaders. The Holy One, blessed be He, attacked Egypt with the tactics employed by a king. The first thing He did was to cut off their water supply, as it is said: And he turned their rivers into blood. They were not contrite, and He therefore brought tumultuous noises upon them. These were the frogs. R. Yosé the son of Hanina said: Their croaking was harder to bear than the havoc they wrought. Still they did not repent, and so he shot arrows at them. These were the gnats, as it is said: And there were gnats upon man, and upon beast (Exod. 8:13). They penetrated the bodies of the Egyptians like spears. However, they did not become contrite, and so He sent barbarians against them. These were the swarms, as it is said: And there came grievous swarms of beasts (ibid., v. 20). Still they did not relent, and so He took other reprisals against them. He brought the murrain: And all the cattle of Egypt died (ibid. 9:6). Nevertheless, they did not repent, and so He poured naphtha over them. These were the boils, as it is said: And a boil breaking forth with blains upon man and upon beast (ibid., v. 9). Still they were not contrite, and so He catapulted projectiles upon them. This was the hail. But even then they did not repent, and so he stirred up a large population against them, that is, the locusts. Even so, they did not mend their ways, and so He imprisoned them. This was the darkness, as it is said: And there was a thick darkness (ibid. 10:22). When they refused to repent, He killed their important men, as it is said: The Lord smote all the firstborn (ibid. 12:19).

(Exod. 10:21:) STRETCH OUT YOUR HAND TOWARD THE HEAVENS. The Holy One brought the plagues upon them in the order¹³Gk.: taxis. of a flesh-and-blood [king]. In the case of a flesh-and-blood king, when a state revolts against him, what does he do? He sends out legions¹⁴Lat.: Legiones. which surround it. First he {smashes} [dams up] their aqueduct.¹⁵Tanh., Exod. 3:4; PRK 7:11; PR 17:7; cf. Exod. R. 17:27. If they repent, well and good; but if not, he brings <war> cries against them. [If they repent, well and good; but if not, he shoots arrows at them. If they repent, well and good; but if not, he brings <the> legions against them. If they repent, well and good; but if not, he brings hand-to-hand combat¹⁶Gk.: dorimachos, literally: “fighting with the spear.” against them.] If they repent, well and good; but if not, he hurls naphtha¹⁷Gk.: naphtha. at them. If they repent, well and good; but if not, he hurls stones at them from a catapult.¹⁸Gk.: balistra. Then, if they repent, well and good; but if not, he stirs up {six legions} a lot of troops¹⁹Gk.: ochloi, i.e., “crowds.” against them. If they repent, well and good; but if not, he binds them in prison. If they repent, well and good; but if not, he kills their noble ones. So did the Holy One come against the Egyptians in the order of kings. First he {smashed} [dammed up] their aqueduct, as stated (in Ps. 78:44): HE TURNED THEIR NILES²⁰The word ye’orehem here would normally be translated “rivers,” but ye’orehem in the singular is also the proper name of the river Nile and reinforces the Egyptian context. INTO BLOOD <SO THAT THEIR STREAMS WERE UNDRINKABLE>. When they did not repent, he brought <war> cries against them. These were the frogs, as stated (in Exod. 8:8): <THEN MOSES CRIED OUT TO THE LORD> ABOUT THE MATTER OF THE FROGS…. Then, when they did not repent, he brought arrows upon them. These were the gnats, as stated (in Exod. 8:13 [17]): AND THERE WERE GNATS [UPON HUMAN AND UPON BEAST], for <each of them > entered an Egyptian body like an arrow. [Then, when they did not repent, he brought <the> legions upon them. These were swarms of flies, as stated (in Ps. 78:45): HE SENT SWARMS OF INSECTS AMONG THEM TO DEVOUR THEM. Then, when they did not repent, he brought hand-to-hand combat upon them, as stated. This is the plague.]²¹Cf. Tanh., Exod. 3:4, which adds here: “And it killed their livestock.” Then, when they did not repent, he hurled naphtha at them. <This corresponds to> the boils. Then, when they did not repent, he hurled stones at them from a catapult. This is the hail. Then when they did not repent even after that, he stirred up a lot of troops against them. These were the locusts. Then after that he put them in prison. [This is the darkness,] as stated (in Exod. 10:21): DARKNESS THAT CAN BE TOUCHED…. Then, when they did not repent, he killed all their eldest sons, as stated (in Exod. 12:29): THAT THE LORD SMOTE ALL THE FIRST-BORN.

“The Lord said to Moses: Say to Aaron: Extend your staff, and strike the dust of the earth, and it will become lice throughout the land of Egypt” (Exodus 8:12).
“The Lord said to Moses: Say to Aaron: Extend your staff, and strike the dust of the earth” – Rabbi Tanḥum said: The Holy One blessed be He said to Moses: ‘It is not proper that the dust that protected you when you killed the Egyptian¹⁵See Exodus 2:12. will be stricken by you.’ Therefore, they were stricken with these three plagues by means of Aaron.¹⁶The first three plagues came from either the water or the dust, both of which had protected Moses in his youth.
“They did so; and Aaron extended his hand with his staff, and struck the dust of the earth, and there were lice upon man, and upon beast; all the dust of the earth became lice throughout the land of Egypt” (Exodus 8:13).
“Aaron extended his hand with his staff” – why did He bring lice upon them? It is because they designated [the Israelites] as sweepers of the streets and the marketplaces; that is why their dust turned into lice. They would dig a square cubit but there was no dust there, as it is stated: “All the dust of the earth became lice.”
“The magicians did so with their spells to bring out the lice, but they could not; and there were gnats upon man, and upon beast” (Exodus 8:14).
“The magicians did so with their spells to bring out the lice, but they could not” – Rabbi Elazar said: From here you learn that a demon is unable to create something smaller than a barley-bulk. The Rabbis say: They cannot even create something the size of a camel; rather, this it can gather and this it cannot gather.¹⁷If the item is smaller than a barley-bulk, the demons cannot even gather it from a different location.
“The magicians said to Pharaoh: It is the finger of God; but Pharaoh’s heart was hardened and he did not heed them, as the Lord had spoken” (Exodus 8:15).
“The magicians said to Pharaoh: It is the finger of God” – when the magicians saw that they were unable to produce the lice, they were immediately aware that the actions were the actions of God and not the action of demons, and they no longer sought to compare themselves to Moses and produce the plagues.