Parshat Naso5 min read

Ketev Meriri, the Noon Demon Psalm 91 Drove Away

Moses recited Psalm 91 on Sinai to ward off demons, and when the Mishkan rose, the noon demon Ketev Meriri lost dominion over the world.

Curated by Arthur · Told by Maggid ·
Table of Contents
  1. What Walked at Midday
  2. The Demon in the Gap Between Shadows
  3. The Day the Mishkan Removed the Demons
  4. What the Protection Required

What Walked at Midday

Moses climbed Mount Sinai every time with a prayer. Not because he was afraid of height or of God. Because of what walked between earth and the divine presence at certain hours, and noon was one of them.

The psalm he recited is the ninety-first. In the tradition it is Moses's psalm, written when he entered the cloud on the mountain. Its language is precise about what it protects against. Terror by night. Arrow by day. Pestilence that walks in darkness. The destroyer that operates at noon. Rabbinic literature reads this line not as poetry but as documentation: the destroyer at noon has a name, and the name is Ketev Meriri.

The Demon in the Gap Between Shadows

Sifrei Devarim, the tannaitic midrash on Deuteronomy from late antiquity, reads the destruction described in Deuteronomy 32 as a profile of specific supernatural forces. The verse about being consumed with hunger and attacked by reshef is glossed as a description of demonic assault. Ketev Meriri operates in the hours between ten in the morning and two in the afternoon, specifically in the shadow-gap of the summer months, between the seventeenth of Tammuz and Rosh Hashanah. It is partially blind, moving through heat, feeding on the desolation that gathers in unshaded places when the sun is highest.

Bamidbar Rabbah 12, the midrash on Numbers compiled in late antiquity, places Psalm 91 directly in Moses's mouth on Sinai. Rav Huna, citing Rav Idi, reads the opening verse, He who dwells in the shelter of the Most High, as a description of Moses entering the cloud. The cloud is the shelter. Moses is the one dwelling in it. The protection promised by the psalm came to him first, and he recited it every time he climbed because the psalm was written from exactly that experience.

The Day the Mishkan Removed the Demons

Midrash Tanchuma Nasso 23 provides the date: the day Moses completed the Tabernacle. The verse in Numbers says, So it came to pass on the day that Moses had finished. Rabbi Johanan read the word for finished, from the Hebrew root klh, as a pun on the word for annihilation from the same root. On the day Moses finished the Mishkan, the destructive demons were annihilated from the world.

Before that day they were ordinary. Ginzberg's Legends of the Jews records that the demons had free range of the earth before the Mishkan stood, wandering wherever they wished. Even Moses had to recite Psalm 91 on every ascent of the mountain to protect himself from them. Then the sanctuary rose and the terms changed. The demons were not all destroyed. But their freedom to move through the human world without restriction ended when the divine presence chose a fixed earthly address.

What the Protection Required

Psalm 91 works as protection in the tradition not because it is a beautiful poem but because it was spoken in the right place at the right time by the right person. Moses spoke it in the divine shelter on the mountain. The psalm's power derives from that original utterance. When Israel recites it, they are repeating the words Moses said when the protection was first needed and first given.

Ketev Meriri is not destroyed by the psalm. It is driven back. It operates in the hours when the sun makes no mercy, when heat accumulates and shadows vanish and the unprotected stand exposed. Psalm 91 is the protection against that exposure. The person who recites it places themselves in the cloud where Moses stood, inside the shelter that a noon demon cannot enter.

After the Mishkan, the rules of demonic presence shifted. The supernatural forces that once wandered freely were constrained by the existence of a place where God's presence concentrated. Ketev Meriri still had the gap between shadows. But it no longer had the whole world.

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From the tradition

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The texts this telling draws on, in full. Open a card to read inline, or expand it for a wider, quieter read.

Sifrei Devarim 321:6Sifrei Devarim

It talks about being "mezei with hunger and embattled by reshef." What does that even mean?

The text interprets "mezei with hunger" as being so desperately hungry that you’re practically hairy with it. Can you The passage then points us to a verse in Jeremiah (14:16) that echoes this image: "And the people to whom they prophesy will be strewn about in the streets of Jerusalem." It’s a powerful image of utter desolation and abandonment.

It gets even stranger.

The text continues, "and cut down by Meriri." Now, who is Meriri? Here, Meriri isn't a who, but a what. It’s identified as a demon. And the text draws a connection: someone "invested" – meaning possessed or afflicted – by a demon becomes rebellious, or "mored" in Hebrew. The text isn't just talking about external forces, like hunger, but internal ones, like demonic influence, leading to rebellion.

And finally, the verse concludes with: "And the tooth of beasts I will send against them." Okay, we're familiar with the idea of wild beasts being dangerous. But this isn't just about a lion attack. The text explains that "His beast will bite and raise (in the victim) a fatal ulcer." It's a bite that leads to something even more insidious, a festering wound that brings death. The text even claims that there have been witnesses to sheep biting and killing!

Sheep!

It's a chilling idea, isn't it? That something as seemingly harmless as a sheep could become an instrument of death.

What are we to make of all this imagery? It's easy to dismiss it as ancient superstition, but perhaps it's more than that. Maybe it's a way of confronting the unpredictable nature of suffering, the feeling that forces beyond our control – whether it's hunger, demonic influence, or even seemingly harmless creatures – can turn against us.

This passage is a stark reminder of the fragility of life and the constant struggle against forces that seek to undermine us. It's a reminder that sometimes, even the most unexpected things can become sources of pain and destruction. And it challenges us to consider what it means to be "invested" by something, whether it's a demon, an idea, or even just overwhelming despair, and how that investment can lead to rebellion and ultimately, to our downfall.

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Bamidbar Rabbah 12:3Bamidbar Rabbah

That image, that feeling, is right at the heart of Psalm 91, and it takes center stage in a fascinating passage from Bamidbar Rabbah 12.

The verse "He who dwells in the shelter of the Most High" (Psalms 91:1) might sound like it's talking about King Solomon, but according to Rav Huna, citing Rav Idi, it's actually about Moses. Moses literally entered a cloud, a "shelter of the Most High," as it says in (Job 22:14), "Clouds are shelter for Him." (Exodus 34:18) tells us, "Moses entered into the midst of the cloud." He stayed there for forty days and forty nights! And that's why he could say, "I will say of the Lord: He is my shelter…" (Psalms 91:2).

The story doesn't stop there. Rabbi Yehuda ben Rabbi Simon, quoting Rabbi Yoḥanan, shares a powerful idea: There were three times Moses recoiled in doubt when God asked something of the Israelites.

First, when God commanded, "Each man shall give a ransom for himself" (Exodus 30:12), Moses wondered, how could anyone afford such a thing? As (Job 2:4) says, "Skin for skin, everything that a man has he will give for his life," and even that wouldn't be enough! (Psalms 49:8)–9 echoes this, saying redemption is "too costly." But God reassures him, "I am not asking according to My ability, but rather, according to their ability" – "this, they shall give" (Exodus 30:13). Rabbi Meir even adds that God showed Moses a coin of fire from beneath the Throne of Glory as an example.

The second instance? When God said, "Command the children of Israel…My offering, My food, for My fires…" (Numbers 28:2), Moses questioned who could possibly provide enough offerings. (Isaiah 40:16) makes the same point, "Lebanon is not sufficient for kindling and its beasts are not sufficient for burnt offerings." Again, God clarifies, "I am not asking according to My ability, but rather, according to their ability"; "This is the fire offering [that you shall bring to the Lord..]" (Numbers 28:3). It’s not about quantity, but about intention, about what they can offer.

And finally, when God commanded, "They shall craft a Sanctuary for Me, and I will dwell in their midst" (Exodus 25:8), Moses was bewildered. How could they build a dwelling place for the Almighty? (1 (Kings 8:2)7) says, "Behold, the heavens and the heaven of heavens cannot contain You." (Isaiah 66:1) asks, "The heavens are My throne, and the earth is My footstool; what house could you build for Me?" God's response? "I am not asking according to My ability, but rather, according to their ability." He only needed a relatively small structure, a mishkan, a tabernacle.

Rabbi Prozedak bar Naḥsha, citing Rabbi Yehuda ben Rabbi Simon, beautifully summarizes: the Almighty rests in the shelter crafted by Betzalel – the Tabernacle. The idea is that God, who dwells in the hidden places, seeks to rest in our shelter.

So, what about the fears that plague us? The psalm speaks of "the terror of night" (Psalms 91:5), which the text connects to demons, even naming Agrat bat Maḥalat. There's also "the arrow that flies by day" (Psalms 91:5), a demon that darts through the air. Rabbi Berekhya suggests that sending the mother bird from the nest (Deuteronomy 22:6–7) can protect you from it.

And then there's "the scourge [ketev] that ravages at noon" (Psalms 91:6). The Rabbis describe it as a demon that plunders strength between the fourth and ninth hours of the day. It's a terrifying image, with a head like a calf and a horn on its forehead. Rabbi Shimon ben Lakish even says that one eye is affixed to its heart, and anyone who sees it dies!

But amidst all this talk of demons and plagues, there's a powerful message of protection. Rav Yitzḥak teaches that even performing one mitzva, like wearing tefillin (phylacteries), brings a thousand angels to protect you. Performing many mitzvot (commandments)? Tens of thousands!

This passage from Bamidbar Rabbah invites us to consider our own "shelter of the Most High." Are we creating a space, both physical and spiritual, where the Divine can dwell? Are we living our lives in a way that invites protection and blessing? Maybe, just maybe, we're more sheltered than we realize.

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Midrash Tanchuma, Nasso 23Midrash Tanchuma

(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.

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Legends of the Jews 3:76Legends of the Jews

See, before the Mishkan was built, the world was apparently crawling with demons. Ginzberg, in Legends of the Jews, recounts how these spirits had free rein, wandering wherever they pleased. It was such a common occurrence that even Moses himself felt the need to recite a special prayer for protection whenever he ascended Mount Sinai. Can you imagine? Every single trip up the mountain, a prayer against demons!

Then, BAM! The Mishkan goes up, and suddenly, peace reigns. Or at least… a new order. The demons' unfettered freedom was revoked. They didn't just vanish completely,. As the text points out, these "pernicious creatures" still lurked, capable of causing harm.

There's a particularly dangerous time of year, a window between the 17th of Tammuz and the 9th of Av, dates marking periods of mourning and remembrance of destruction in Jewish history. During these weeks, tradition says the demons' power is at its peak. It’s a somber thought, isn't it? That even within sacred time, shadows can linger.

Even among demons, there are hierarchies. And the most terrifying of them all? A being called Keteb.

Now, Keteb isn't your garden-variety demon. The legends paint a truly horrific picture. Just seeing him could be fatal, to both humans and animals! He's described as rolling like a ball, with the head of a calf and a single horn jutting from his forehead. Imagine that image for a moment. A monstrous, rolling calf-headed entity whose mere presence means death.

Yikes.

What does this all mean? Perhaps it’s a symbolic representation of the chaos that holiness seeks to contain. Maybe it’s a reminder that even in the most sacred spaces, there's always a struggle against darkness. Or maybe, just maybe, it's a glimpse into a world we can barely comprehend, a world where the building of a sanctuary has cosmic consequences.

Whatever the interpretation, these legends remind us that the stories we tell ourselves, the myths we create, are often reflections of our deepest fears and our highest hopes. And that even when we build our Mishkan, our sacred spaces, there's still a need for vigilance, for prayer, and maybe, just maybe, for a little bit of extra protection.

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