Êxodo 10:15 Midrash: Midrash Tanchuma Buber, Mekhilta DeRabbi Yishmael & Shemot Rabbah

Whatever the Egyptians devised against Israel, [the Holy One] brought against them. Those < Egyptians > devised for them to draw their water. What is written (in Ps. 78:44)? HE TURNED THEIR NILES INTO BLOOD SO THAT THEIR STREAMS WERE UNDRINKABLE. Those < Egyptians > devised for them to be laden as traveling traders.²²Gk.: pragmateutes. He sent frogs upon them and covered them with resin. Those < Egyptians > devised for them to work on the land. The Holy One made the land swarm with gnats. Those <Egyptians> devised that they should bear their children as a paidagogos.²³The Greek word designates a slave who was assigned to a child as an attendant and guardian. He sent lions, wolves, and bears among them. <If> an Egyptian had ten children, when he told Israel to bring them to the market place, the lion came and took one, the wolf one, the bear one, the leopard one, and the snake one. Then he came <back> to the Egyptian alone. The Egyptian said: Where are my children? Israel said to him: Sit down and I myself will render you an accounting: The lion took one <etc.>; and so <he continued> on, until he had given him an accounting. Now they (the Egyptians) devised that they would tend their livestock, but he sent out the plague among them, as stated (in Exod. 9:6): THEN ALL THE EGYPTIAN LIVESTOCK DIED. They intended that they would be bath attendants {bathe them}. He brought the boils upon them. They intended to stone them with stones. The Holy One brought the hail upon them, as stated (in Exod. 9:22): THAT THERE MAY BE HAIL <IN ALL THE LAND OF EGYPT >…. They intended that they would be their vine dressers. The Holy One brought the locusts, who ate their trees, as stated (in Exod. 10:15): AND THEY ATE ALL THE GRASS OF THE EARTH…. They intended to imprison them in prison. The Holy One brought darkness upon them, as stated (in Exod. 10:23): THEY COULD NOT SEE ONE ANOTHER…. They intended to kill them. The Holy One killed their first-born, as stated (in Exod. 12:29): THAT THE LORD SMOTE ALL THE FIRST-BORN. They intended to drown them in water. The Holy One also drowned them in water, as stated (in Ps. 136:15): BUT OVERTHREW PHARAOH AND HIS HOST IN THE REED SEA….

And thus with Egypt, viz. (Exodus 10:15) "And the L–rd swept an east wind over the land." And thus do you find with the ten tribes, that the L–rd exacted punishment of them with an east wind, viz. (Hoshea 13:15) "For he (Ephraim) flourished among the reeds. (But now) an east wind will come, a wind from the L–rd, rising from the desert, and it will dry up his source and parch his spring. It will despoil the source of all his precious vessels."

“The Lord said to Moses: Extend your hand over the land of Egypt for the locusts, and they will ascend on the land of Egypt, and eat every grass of the land, everything that the hail left” (Exodus 10:12).
“The Lord said to Moses: Extend your hand” – why did He bring locusts upon them? It is because they tasked Israel to be sowers of wheat and barley; therefore, he brought locusts upon them, and they ate everything that the Israelites had sown.
“Moses extended his staff over the land of Egypt, and the Lord brought an east wind upon the land all that day, and all the night; it was morning, and the east wind brought the locusts” (Exodus 10:13).
“Moses extended his staff” – why would the Holy One blessed be He give a time for the plagues, “tomorrow” (Exodus 10:4), and not bring them upon them immediately? It was so they would relent and repent.
Pharaoh hastened to call Moses and Aaron, and he said: I have sinned against the Lord your God, and against you (Exodus 10:16).
“The locusts ascended…they covered the surface of the entire land… Pharaoh hastened to call Moses and Aaron…” (Exodus 10:14–16) – what is “I have sinned against the Lord your God, and against you”? “I have sinned against the Lord your God,” in that I did not let Israel go, “and against you,” in that I drove you out from before me and I thought to curse you, as I said: “So let the Lord be with you” (Exodus 10:10). “Now, please, forgive my sin [just this once, and entreat the Lord your God, and He will remove this death only from me].… He exited from Pharaoh” (Exodus 10:17–18).