Daniel and Karl delve into Jewish mysticism (and a little Christian mysticism, too) as they discuss Exodus Ch. 10. You can listen using the player below or by subscribing through iTunes. The midrash that Daniel provided is below the player.
(Zohar, 10:1) G‑d said to Moses: “Come in to Pharaoh”
Rabbi Shimon [bar Yochai] continued: It is now fitting to reveal mysteries connected with that which is above and that which is below. Why is it written, “Come in to Pharaoh”? Ought it not rather have said, “Go to Pharaoh”? It is to indicate that G‑d brought Moses into a chamber within a chamber, into the abode of the supernal mighty serpent that is the soul of Egypt, from whom many lesser serpents emanate. Moses was afraid to approach him, because his roots are in supernal regions, and he approached only his subsidiary streams. When G‑d saw that Moses feared the serpent, He said, “Come in to Pharaoh.”
(Midrash HaGadol, 10:1) For I have hardened his heart and the heart of his servants
When Pharaoh would soften, his servants and ministers would harden themselves; when they would soften, Pharaoh would harden; when both would soften, G‑d would harden their hearts.
(Rashi, 10:10) See that evil is before your faces:
[Understand this] as the Targum [Onkelos] renders it. I have [also] heard an Aggadic midrash, however [which explains the passage as follows]: There is a star named Ra’ah [i.e., רָעָה meaning evil]. Pharaoh said to them [Moses and Aaron], “With my astrology I see that star ascending toward you in the desert [where you would like to go], and that is a sign of blood and slaughter.” When the Israelites sinned with the calf, and the Holy One, blessed be He, sought to kill them, Moses said in his prayer, “Why should the Egyptians say, ‘With Ra’ah He took them out…?’” (Exod. 32:12) This is what he [Pharaoh] said to them, “See that Ra’ah [evil] is opposite your faces,” [implying that their blood would be shed in the desert]. Immediately, “The Lord repented of the Ra’ah [the sign of the star]” (Exod. 32:14), and He turned the bloodshed [symbolized by this star] into the blood of the circumcision, for Joshua [in fact] circumcised them. This is the meaning of what is said: “This day I have rolled away the reproach of the Egyptians from you” (Josh. 5:9), for they were saying to you, “We see blood over you in the desert.” -[from Midrash Shir Hashirim, Wertheimer 1:2]
(Rashi, 10:11) Not so:
As you have said [that you want] to take the young children with you, but let the men go and worship the Lord.
(Rashi, 10:14) and after it, there will never be one like it:
And the one [the locust plague] that took place in the days of Joel, about which it is said: “the like of which has never been” (Joel 2:2), [from which] we learn that it was more severe than that of [the plague in the days of] Moses-namely because that one was [composed] of many species [of locusts] that were together: arbeh, yelek, chasil, [and] gazam; but [the locust plague] of Moses consisted of only one species [the arbeh], and its equal never was and never will be.
(Midrash Rabbah, 10:19) G‑d turned a very strong west wind, which took away the locusts and cast them into the Sea of Reeds; there remained not one locust in all the borders of Egypt
When the locusts first came, the Egyptians rejoiced and said: “Let us gather them and fill barrels with them.” Then did G‑d say: “Wretches! Will you rejoice with the plagues I have brought upon you?” Immediately, “G‑d turned a very strong west wind . . . there remained not one locust in all the borders of Egypt”—even those that had been pickled in their pots and barrels took wing and fled.
(Midrash Rabbah, 10:21) Stretch out your hand towards heaven, that there shall be darkness over the land of Egypt
Why did G‑d . . . bring darkness upon the Egyptians? Because there were transgressors in Israel who had Egyptian patrons and who lived in affluence and honor, and were unwilling to leave. So G‑d said: “If I bring upon them publicly a plague from which they will die, the Egyptians will say: ‘Just as it has passed over us, so has it passed over them.’” Therefore He brought darkness upon the Egyptians for three days, so that the [Israelites] should bury their dead without their enemies seeing them.
(Midrash Rabbah, 10:23) A man did not see his fellow, nor did anyone get up from his place for three days
There were six days of darkness. . . . During the first three, “a man did not see his fellow”; during the last three days, one who was sitting could not stand up, one who was standing could not sit down, and one who was lying down could not raise himself upright.
(Chiddushei HaRim) There is no greater darkness than one in which “a man did not see his fellow”—in which a person becomes oblivious to the needs of his fellow man. When that happens, a person becomes stymied in his personal development as well—“nor did anyone get up from his place.”
(Rashi, 10:29) You have spoken correctly: You have spoken appropriately, and you have spoken at the right time. It is true that I shall no longer see your face. — [from Mechilta on Exod. 12:31]