(Numb. 7:1:) “So it came to pass on the day that Moses had finished.” R. Johanan said, “What is the meaning of ‘on the day that [Moses] had finished (rt.: klh)?’ [Finished is] a word for annihilation (rt.: klh). On the day that the Tabernacle was erected the destructive demons (mazziqin) were annihilated (rt.: klh) from the world.”
Before that Tabernacle was erected, the destructive demons had been common in the world. When Moses went up on the mountain, he said this psalm (i.e., Ps. 91, which begins), “Whoever dwells in the shelter of the Most High,” in that he (Moses) did dwell in the shelter of the Holy One, blessed be He. (Ibid., cont.:) “He lodges in the shadow (tsel) of the Almighty,” in that he lodged there a hundred and twenty days, like the numerical count of [the letters in the word,] tsel. (Vs. 2) “[I will] say to the Lord, my refuge [and my fortress (metsudah)],” in that He is my refuge and has become like a wall for me. (Ibid., cont.:) “My God, in whom I trust.” The Holy One, blessed be He, said to him, “You have put your trust in Me; by your life, I am standing up for you.” (Vs. 3:) “That he will deliver you from the snare of the fowler.” What is the meaning of “from the snare of the fowler?”
From the trap of David, who [would have been] seized to be killed, as stated (in II Sam. 23:26) “and Saul and his men were trying to encircle David and his men and capture them.” (Vs. 4:) “You will take refuge under His wings; His truth is a shield and buckler.”
Resh Laqish said, “I have become a shield for whoever takes refuge in the Torah.” (Vs. 5:) “You shall not be afraid of any terror by night.” From here [we learn] that they were afraid of destructive demons. (Ibid., cont.:) “Nor of the arrow that flies by day.” R. Berekhyah the Priest Berabbi said, “There is a destructive demon (mazziq) that flies like a bird and shoots forth like an arrow.” (Vs. 6:) “Of the pestilence that walks in the darkness, of the plague that lays waste at noonday.”
This is the plague demon, Meriri; for whoever sees him will not survive in the world, whether he be human, cattle, or wild beast. How is he made? His head resembles a calf with one horn coming out of the middle of his forehead, and he is made of obsidian. And Meriri has dominion from the seventeenth of Tammuz (around July) to the ninth of Av (around August). [It is] therefore [written] (in vs. 6), “of the plague that lays waste at noonday.” (Vs. 10:) “There shall no evil come unto you, neither shall pestilence come near your tent.” This is the tent of meeting.
Ergo, until the day that the Tabernacle was erected, the destructive demons (mazziqin) were common, and on the day that the Tabernacle was erected they were annihilated (rt.: klh). R. Simeon b. Laqish said, “What [reason] is there for me to learn [this] from the book of Psalms? It is [to be] learned from its [proper] place (in Numb. 6:24), “The Lord bless you and keep you” [from the destructive demons] and from all evil. When? On the day that the Tabernacle was erected.