Korach for our Times
(א) וַיִּקַּ֣ח קֹ֔רַח בֶּן־יִצְהָ֥ר בֶּן־קְהָ֖ת בֶּן־לֵוִ֑י וְדָתָ֨ן וַאֲבִירָ֜ם בְּנֵ֧י אֱלִיאָ֛ב וְא֥וֹן בֶּן־פֶּ֖לֶת בְּנֵ֥י רְאוּבֵֽן׃ (ב) וַיָּקֻ֙מוּ֙ לִפְנֵ֣י מֹשֶׁ֔ה וַאֲנָשִׁ֥ים מִבְּנֵֽי־יִשְׂרָאֵ֖ל חֲמִשִּׁ֣ים וּמָאתָ֑יִם נְשִׂיאֵ֥י עֵדָ֛ה קְרִאֵ֥י מוֹעֵ֖ד אַנְשֵׁי־שֵֽׁם׃
(1) Now Korah, son of Izhar son of Kohath son of Levi, betook himself, along with Dathan and Abiram sons of Eliab, and On son of Peleth—descendants of Reuben— (2) to rise up against Moses, together with two hundred and fifty Israelites, chieftains of the community, chosen in the assembly, men of repute.
דתן ואבירם. בִּשְׁבִיל שֶׁהָיָה שֵׁבֶט רְאוּבֵן שָׁרוּי בַּחֲנִיָּתָם תֵּימָנָה שָׁכֵן לִקְהָת וּבָנָיו הַחוֹנִים תֵּימָנָה, נִשְׁתַּתְּפוּ עִם קֹרַח בְּמַחֲלָקְתּוֹ — "אוֹי לָרָשָׁע אוֹי לִשְׁכֵנוֹ". וּמָה רָאָה קֹרַח לַחֲלֹק עִם מֹשֶׁה? נִתְקַנֵּא עַל נְשִׂיאוּתוֹ שֶׁל אֱלִיצָפָן בֶּן עֻזִּיאֵל, שֶׁמִּנָּהוּ מֹשֶׁה נָשִׂיא עַל בְּנֵי קְהָת עַל פִּי הַדִּבּוּר, אָמַר קֹרַח, אַחֵי אַבָּא אַרְבָּעָה הָיוּ, שֶׁנֶּאֱמַר (שמות ו') "וּבְנֵי קְהָת" וְגוֹ', עַמְרָם הַבְּכוֹר נָטְלוּ שְׁנֵי בָנָיו גְּדֻלָּה, אֶחָד מֶלֶךְ וְאֶחָד כֹּהֵן גָּדוֹל, מִי רָאוּי לִטֹּל אֶת הַשְּׁנִיָּה? לֹא אֲנִי שֶׁאֲנִי בֶּן יִצְהָר, שֶׁהוּא שֵׁנִי לְעַמְרָם, וְהוּא מִנָּה נָשִׂיא אֶת בֶּן אָחִיו הַקָּטָן מִכֻּלָּם, הֲרֵינִי חוֹלֵק עָלָיו וּמְבַטֵּל אֶת דְּבָרָיו. מֶה עָשָׂה? עָמַד וְכָנַס ר"נ רָאשֵׁי סַנְהֶדְרָאוֹת — רֻבָּן מִשֵּׁבֶט רְאוּבֵן שְׁכֵנָיו וְהֵם אֱלִיצוּר בֶּן שְׁדֵיאוּר וַחֲבֵרָיו וְכַיּוֹצֵא בוֹ, שֶׁנֶּאֱמַר נְשִׂיאֵי עֵדָה קְרִאֵי מוֹעֵד וּלְהַלָּן הוּא אוֹמֵר (במדבר א') "אֵלֶּה קְרוּאֵי הָעֵדָה" — וְהִלְבִּישָׁן טַלִּיתוֹת שֶׁכֻּלָּן תְּכֵלֶת, בָּאוּ וְעָמְדוּ לִפְנֵי מֹשֶׁה, אָמְרוּ לוֹ טַלִּית שֶׁכֻּלָּהּ שֶׁל תְּכֵלֶת חַיֶּבֶת בְּצִיצִית אוֹ פְטוּרָה? אָמַר לָהֶם חַיֶּבֶת, הִתְחִילוּ לִשְׂחֹק עָלָיו, אֶפְשָׁר טַלִּית שֶׁל מִן אַחֵר חוּט אֶחָד שֶׁל תְּכֵלֶת פּוֹטְרָהּ, זוֹ שֶׁכֻּלָּהּ תְּכֵלֶת לֹא תִפְטֹר אֶת עַצְמָהּ? (תנחומא):
ודתן ואבירם AND DATHAN AND ABIRAM — Because the tribe of Reuben had their place, when they encamped, in the South, thus being neighbours of Kohath and his sons, who, too, encamped in the South (cf. Numbers 3:29), they (the Reubenites) joined Korah in his quarrel. “Woe to the wicked, woe to his neighbour!” — And what induced Korah to quarrel with Moses? He was envious of the princely dignity held by Elzaphan the son of Uziel (Midrash Tanchuma, Korach 1) whom Moses had appointed prince over the sons of Kohath although this was by the express command of God (Numbers 3:30). Korah argued thus: “My father and his brothers were four in number — as it is said, (Exodus 6:18) “and the sons of Kohath were [Amram and Izhar and Hebron and Uziel]”. — “As to Amram, the eldest, his two sons have themselves assumed high dignity, one as king and the other as High Priest; who is entitled to receive the second (the rank next to it)? Is it not “I” who am the son of Izhar, who was the second to Amram amongst the brothers? And yet he has appointed as prince the son of his (Amram’s) brother who was the youngest of all of them! I hereby protest against him and will undo his decision”. — What did he do? He arose and assembled 250 men, fitted to be heads of the Sanhedrin, most of them of the tribe of Reuben who were his neighbours, viz., Elizur the son of Shedeur, (the prince of the tribe of Reuben; cf. Numbers 1:5), and his colleagues, and others of a similar standing, — for here it states (v. 2) that they were “princes of the congregation, those who were called to the assembly (קראי מועד)”, and there (in another passage) it states, (Numbers 1:16) “these were they who were called to the congregation (קרואי העדה)” (amongst whom was also Elizur the son of Shedeur; cf. Numbers 1:5 and Rashi on Numbers 1:16), — and he attired them in robes of pure purple wool. They then came and stood before Moses and said to him, “Is a garment that is entirely of purple subject to the law of Zizith or is it exempt”? He replied to them: “It is subject to that law”. Whereupon they began to jeer at him: “Is this possible? A robe of any different coloured material, one thread of purple attached to it exempts it, and this that is entirely of purple should it not exempt itself (i.e. ipso facto be exempt) from the law of “Zizith”? (Midrash Tanchuma, Korach 2).
דתן שעבר על דת אל אבירם שאיבר עצמו מעשות תשובה ואון שישב באנינות פלת שנעשו לו פלאות בן ראובן בן שראה והבין
The Gemara proceeds to interpret the names of Korah’s cohorts: “Dathan and Abiram, the sons of Eliab, and On, the son of Peleth, sons of Reuben” (Numbers 16:1). “Dathan” is one who violated the precepts [dat] of God. “Abiram” is one who braced [iber] himself from repenting. “And On” indicates one who sat in acute mourning [aninut] over the sin that he committed, and he repented and was spared. “Peleth” is one for whom wonders [pelaot] were performed. Son of Reuben [Reuven], is a son who saw and understood [ra’a vehevin] the nature of what was transpiring and repented.
אמר רב און בן פלת אשתו הצילתו אמרה ליה מאי נפקא לך מינה אי מר רבה אנת תלמידא ואי מר רבה אנת תלמידא אמר לה מאי אעביד הואי בעצה ואשתבעי לי בהדייהו אמרה ליה ידענא דכולה כנישתא קדישתא נינהו דכתיב (במדבר טז, ג) כי כל העדה כולם קדושים אמרה ליה תוב דאנא מצילנא לך אשקיתיה חמרא וארויתיה ואגניתיה גואי אותבה על בבא
Rav says: On, son of Peleth, did not repent on his own; rather, his wife saved him. She said to him: What is the difference to you? If this Master, Moses, is the great one, you are the student. And if this Master, Korah, is the great one, you are the student. Why are you involving yourself in this matter? On said to her: What shall I do? I was one of those who took counsel and I took an oath with them that I would be with them. She said to him: I know that the entire assembly is holy, as it is written: “For all the assembly is holy” (Numbers 16:3), and they observe the restrictions of modesty. She said to him: Sit, for I will save you. She gave him wine to drink and caused him to become drunk and laid him on a bed inside their tent. She sat at the entrance of the tent
וסתרתה למזיה כל דאתא חזיה הדר אדהכי והכי אבלעו להו
and exposed her hair as though she were bathing. Anyone who came and saw her stepped back. In the meantime the assembly of Korah was swallowed into the ground, and On, son of Peleth, was spared.

(יז) כָּל מַחֲלֹקֶת שֶׁהִיא לְשֵׁם שָׁמַיִם, סוֹפָהּ לְהִתְקַיֵּם. וְשֶׁאֵינָהּ לְשֵׁם שָׁמַיִם, אֵין סוֹפָהּ לְהִתְקַיֵּם. אֵיזוֹ הִיא מַחֲלֹקֶת שֶׁהִיא לְשֵׁם שָׁמַיִם, זוֹ מַחֲלֹקֶת הִלֵּל וְשַׁמַּאי. וְשֶׁאֵינָהּ לְשֵׁם שָׁמַיִם, זוֹ מַחֲלֹקֶת קֹרַח וְכָל עֲדָתוֹ:

(17) Every dispute that is for the sake of Heaven, will in the end endure; But one that is not for the sake of Heaven, will not endure. Which is the controversy that is for the sake of Heaven? Such was the controversy of Hillel and Shammai. And which is the controversy that is not for the sake of Heaven? Such was the controversy of Korah and all his congregation.