(כז) וַיֵּעָל֗וּ מֵעַ֧ל מִשְׁכַּן־קֹ֛רֶח דָּתָ֥ן וַאֲבִירָ֖ם מִסָּבִ֑יב וְדָתָ֨ן וַאֲבִירָ֜ם יָצְא֣וּ נִצָּבִ֗ים פֶּ֚תַח אָֽהֳלֵיהֶ֔ם וּנְשֵׁיהֶ֥ם וּבְנֵיהֶ֖ם וְטַפָּֽם׃ (כח) וַיֹּאמֶר֮ מֹשֶׁה֒ בְּזֹאת֙ תֵּֽדְע֔וּן כִּֽי־יְהוָ֣ה שְׁלָחַ֔נִי לַעֲשׂ֕וֹת אֵ֥ת כָּל־הַֽמַּעֲשִׂ֖ים הָאֵ֑לֶּה כִּי־לֹ֖א מִלִּבִּֽי׃ (כט) אִם־כְּמ֤וֹת כָּל־הָֽאָדָם֙ יְמֻת֣וּן אֵ֔לֶּה וּפְקֻדַּת֙ כָּל־הָ֣אָדָ֔ם יִפָּקֵ֖ד עֲלֵיהֶ֑ם לֹ֥א יְהוָ֖ה שְׁלָחָֽנִי׃ (ל) וְאִם־בְּרִיאָ֞ה יִבְרָ֣א יְהוָ֗ה וּפָצְתָ֨ה הָאֲדָמָ֤ה אֶת־פִּ֙יהָ֙ וּבָלְעָ֤ה אֹתָם֙ וְאֶת־כָּל־אֲשֶׁ֣ר לָהֶ֔ם וְיָרְד֥וּ חַיִּ֖ים שְׁאֹ֑לָה וִֽידַעְתֶּ֕ם כִּ֧י נִֽאֲצ֛וּ הָאֲנָשִׁ֥ים הָאֵ֖לֶּה אֶת־יְהוָֽה׃ (לא) וַיְהִי֙ כְּכַלֹּת֔וֹ לְדַבֵּ֕ר אֵ֥ת כָּל־הַדְּבָרִ֖ים הָאֵ֑לֶּה וַתִּבָּקַ֥ע הָאֲדָמָ֖ה אֲשֶׁ֥ר תַּחְתֵּיהֶֽם׃ (לב) וַתִּפְתַּ֤ח הָאָ֙רֶץ֙ אֶת־פִּ֔יהָ וַתִּבְלַ֥ע אֹתָ֖ם וְאֶת־בָּתֵּיהֶ֑ם וְאֵ֤ת כָּל־הָאָדָם֙ אֲשֶׁ֣ר לְקֹ֔רַח וְאֵ֖ת כָּל־הָרֲכֽוּשׁ׃
(27) So they withdrew from about the abodes of Korah, Dathan, and Abiram. Now Dathan and Abiram had come out and they stood at the entrance of their tents, with their wives, their children, and their little ones. (28) And Moses said, “By this you shall know that it was the LORD who sent me to do all these things; that they are not of my own devising: (29) if these men die as all men do, if their lot be the common fate of all mankind, it was not the LORD who sent me. (30) But if the LORD brings about something unheard-of, so that the ground opens its mouth and swallows them up with all that belongs to them, and they go down alive into Sheol, you shall know that these men have spurned the LORD.” (31) Scarcely had he finished speaking all these words when the ground under them burst asunder, (32) and the earth opened its mouth and swallowed them up with their households, all Korah’s people and all their possessions.
(9) The sons of Eliab were Nemuel, and Dathan and Abiram. These are the same Dathan and Abiram, chosen in the assembly, who agitated against Moses and Aaron as part of Korah’s band when they agitated against the LORD. (10) Whereupon the earth opened its mouth and swallowed them up with Korah—when that band died, when the fire consumed the two hundred and fifty men—and they became an example. (11) The sons of Korah, however, did not die.
(במדבר כו, יא) ובני קרח לא מתו תנא משום רבינו אמרו מקום נתבצר להם בגיהנם וישבו עליו ואמרו שירה אמר רבה בר בר חנה זימנא חדא הוה קאזלינא באורחא אמר לי ההוא טייעא תא ואחוי לך בלועי דקרח אזיל חזא תרי בזעי דהוה קא נפק קיטרא מנייהו שקל גבבא דעמרא אמשיי' מיא ואותביה בריש רומחיה ואחלפי' התם איחרך א"ל אצית מה שמעת ושמעית דהוו קאמרי הכי משה ותורתו אמת והן בדאים
"And the children of Korach did not die." It was taught in the name of our Rabbi: they were gathered and put in a place in Gehennom where they stayed and recited a song.
Rabbah bar bar Chanah said: One time, I was walking along the road. An arab merchant said to me, "Come, and I will show you "the swallowed ones of Korach."" He went and showed two cracks [in the ground] and smoke was coming out of it.... He said to me, "Listen to what you're about to hear." I heard that they were singing, "Moshe and his Torah are True, and we were wrong!"
What song were the children of Korach singing?
--> Maharsha: Tehillim 88
--> Zohar: Tehillim 48
According to the Zohar's understanding, why would Bnei Korach sing this particular chapter of Tehillim?
--> Korach instigated an insurrection, a division amongst the Israelites. Tehillim 48 looks to Jerusalem as a unifying force, a space that will be united in the future yemot HaMashiach.
--> A further connection is that it is sung as shir shel yom for Mondays. Monday was the only day of Bereishit in which the phrase "ki tov" was not uttered, due to the fact that on that day division - havdalah - was brought into the world, through the separation of mayim va'rakia.