Where the Plague of Darkness Came From in Midrash Tanchuma

Another interpretation of "Stretch out your hand toward the heavens" (Exodus 10:21). From where did the darkness come? Rabbi Judah and Rabbi Nehemiah. Rabbi Judah says: from the darkness above, as it is said, "He made darkness His hiding place" (Psalms 18:12). Rabbi Nehemiah says: from the darkness of Gehinnom, as it is said, "A land of gloom, like darkness" (Job 10:22). Rabbi Joshua ben Levi said: In three places we have heard that a person recites his teaching close to his death. As it is said, "to make known to you the certainty of words of truth, that you may answer words of truth to those who sent you" (Proverbs 22:21). And likewise Solomon said, "The end of the matter, all has been heard" (Ecclesiastes 12:13). What is "the shadow of death and no order" (Job 10:22)? Once a person is in the shadow of death, he orders his teaching. Rabbi Tanchuma bar Abba [said]: When he comes to depart, the ministering angels say to him, "Ascribe strength to God" (Psalms 68:35). And likewise it says, "Thus said the Lord [God]: On the day he went down to Sheol" (Ezekiel 31:15). Hence "a land of gloom, like darkness." Rabbi Judah says: With what are the wicked covered when they go down to Sheol? With darkness. Hezekiah said: A vat—with what does one cover it? With an earthenware vessel of the same kind as itself; just as it is of earthenware, so one covers it only with earthenware. So too the wicked, what is written concerning them? "And their deeds are in darkness" (Isaiah 29:15). Therefore the Holy One, blessed be He, brings them down to Sheol, which is dark, and covers over them the deep, which is darkness, as it is said, "and darkness was upon the face of the deep" (Genesis 1:2). Hence, that darkness which came upon the Egyptians came from within Gehinnom. And how thick was that darkness? Our Rabbis said: as thick as a Gordian denarius (that is, the name of a place), "and the darkness grew dense" (Exodus 10:21).