Midrash Tanchuma, Korach 8

וַיְדַבֵּר ה' אֶל מֹשֶׁה לֵאמֹר, דַּבֵּר אֶל הָעֵדָה לֵאמֹר הֵעָלוּ מִסָּבִיב. וְאַף עַל פִּי שֶׁשָּׁמַע מֹשֶׁה מִפִּי הַגְּבוּרָה כָּךְ, לֹא אָמַר לָהֶם עַד שֶׁהָלַךְ וְהִתְרָה בָּהֶן, שֶׁנֶּאֱמַר: וַיָּקָם מֹשֶׁה וַיֵּלֵךְ אֶל דָּתָן וַאֲבִירָם. לְהוֹדִיעַ רִשְׁעָתָן, שֶׁאַף עַל פִּי שֶׁהָלַךְ מֹשֶׁה בְּרַגְלָיו אֵצֶל הָרְשָׁעִים, הָיוּ קָשִׁים לִרְצוֹת. מֶה עָשׂוּ. לֹא רָצוּ לָצֵאת מֵאָהֳלֵיהֶם כְּנֶגְדוֹ. כְּשֶׁרָאָה מֹשֶׁה כָּךְ, אָמַר עַד כָּאן הָיָה עָלַי לַעֲשׂוֹת. מִיָּד, וַיְדַבֵּר אֶל הָעֵדָה לֵאמֹר סוּרוּ נָא מֵעַל וְגוֹ'. שָׁנוּ רַבּוֹתֵינוּ, אַרְבָּעָה נִקְרְאוּ רְשָׁעִים, אֵלּוּ הֵן, הַפּוֹשֵׁט יָדוֹ לַחֲבֵרוֹ לְהַכּוֹתוֹ, אַף עַל פִּי שֶׁלֹּא הִכָּהוּ, נִקְרָא רָשָׁע, שֶׁנֶּאֱמַר: וַיֹּאמֶר לָרָשָׁע לָמָּה תַּכֶּה רֵעֶךָ (שמות ב, יג). הִכִּיתָ לֹא נֶאֱמַר, אֶלָּא תַּכֶּה. וְהַלֹּוֶה וְאֵינוֹ מְשַׁלֵּם, שֶׁנֶּאֱמַר: לֹוֶה רָשָׁע וְלֹא יְשַׁלֵּם (תהלים לז, כא). וּמִי שֶׁיֵּשׁ בּוֹ עַזּוּת פָּנִים וְאֵינוֹ מִתְבַּיֵּשׁ לִפְנֵי מִי שֶׁגָּדוֹל מִמֶּנּוּ, שֶׁנֶּאֱמַר: הֵעֵז אִישׁ רָשָׁע בְּפָנָיו (משלי כא, כט). וּמִי שֶׁהוּא בַּעַל מַחֲלֹקֶת, שֶׁנֶּאֱמַר: סוּרוּ נָא מֵעַל אָהֳלֵי הָאֲנָשִׁים הָרְשָׁעִים. וּשְׁנֵיהֶם הָיוּ בְּדָתָן וַאֲבִירָם, עַזּוּת פָּנִים וּמַחֲלֹקֶת. מַחֲלֹקֶת בְּאוֹתִיּוֹתָיו נִדְרָשׁ, מ' מָרָה, ח' חָרוֹן, ל' לוֹקִין, ק' קְלָלָה, ת' תּוֹעֵבָה וְיֵשׁ אוֹמְרִים: תַּכְלִית כְּלָיָה מֵבִיא לָעוֹלָם. וַיַּעֲלוּ מֵעַל מִשְׁכַּן קֹרַח דָּתָן וַאֲבִירָם. כֵּיוָן שֶׁרָאוּ כָּךְ שֶׁנִּסְתַּלְּקוּ יִשְׂרָאֵל מִסְּבִיבוֹתֵיהֶם, יָצְאוּ מְחָרְפִין וּמְגַדְּפִין, שֶׁנֶּאֱמַר: יָצְאוּ נִצָּבִים. וּלְהַלָּן כְּתִיב: וַיִּגַּשׁ הַפְּלִשְׁתִּי הַשְׁכֵּם וְהַעֲרֵב וַיִּתְיַצֵּב אַרְבָּעִים יוֹם (ש״‎א יז, טז). פָּתַח מֹשֶׁה וְאָמַר, כְּדִכְתִּיב, וַיֹּאמֶר מֹשֶׁה בְּזֹאת תֵּדְעוּן כִּי ה' שְׁלָחַנִי וְגוֹ', אִם כְּמוֹת כָּל הָאָדָם יְמוּתוּן אֵלֶּה. מָשָׁל לְמָה הַדָּבָר דּוֹמֶה. לְשׁוֹשְׁבִין בִּתּוֹ שֶׁל מֶלֶךְ שֶׁהָיוּ עֵדוֹתֶיהָ בְּיָדוֹ. עָמַד אֶחָד מִן הַמְּסֻבִּין כְּנֶגְדוֹ וְקִלֵּל אֶת הַשּׁוֹשְׁבִין, וְאָמַר לֵיהּ: לֹא הָיוּ בְּתוּלִים לְבִתּוֹ שֶׁל מֶלֶךְ. עָמַד הַשּׁוֹשְׁבִין כְּנֶגֶד הַמֶּלֶךְ וְאָמַר לֵיהּ: אִם אֵין אַתָּה מוֹצִיא אֶת זֶה לְהָרְגוֹ בִּפְנֵי הַכֹּל, הֲרֵינִי אוֹמֵר, בְּוַדַּאי שֶׁלֹּא נִמְצְאוּ בְּתוּלִים לְבִתּוֹ שֶׁל מֶלֶךְ. מִיָּד אָמַר הַמֶּלֶךְ, מוּטָב לִי לַהֲרֹג אֶת זֶה וְלֹא יוֹצִיא הַשּׁוֹשְׁבִין שָׁם רַע עַל בִּתִּי. וְכָךְ קֹרַח נֶחְלַק עַל מֹשֶׁה, וְאָמַר, מִלִּבּוֹ וּמֵעַצְמוֹ אָמַר מֹשֶׁה אֶת כָּל הַדִּבְּרוֹת הָאֵלֶּה. פָּתַח מֹשֶׁה וְאָמַר, בְּזֹאת תֵּדְעוּן כִּי ה' שְׁלָחַנִי, אִם כְּמוֹת כָּל הָאָדָם יְמוּתוּן אֵלֶּה אַף אֲנִי אוֹמֵר, לֹא ה' שְׁלָחַנִי, וּמִלִּבִּי אָמַרְתִּי. (Numb. 16:23–24:) “And the Lord spoke […], ‘Speak unto the congregation, saying, “Get away from about [the dwellings of Korah, Dathan and Abiram].”’” Although Moses heard it from the mouth of the Almighty,³⁷Numb. R. 18:12. he did not tell them to get away until he had gone and warned them, as stated (in vs. 25), “Then Moses arose and went unto Dathan and Abiram.” [This serves] to make their wickedness known, for although Moses went to them on foot, the[se] wicked ones were too stubborn to make amends. What did they do? They were unwilling to come out of their tents to face him. When Moses saw this, he said, “This much [only] it was incumbent upon me to do.” Immediately (in Numb. 16:26) “And he spoke to the congregation, ‘Please move away from [the tents of these wicked people.]’” Our masters have taught: Four [types of people] are called wicked:³⁸Numb. R. 18:12, cont.; cf. PRK 30 (p.190b in Buber text; “Additional Piska” 28:2 in Braude’s translation). The one who extends his hand against his companion to strike him. Even though he did not [actually] strike him, he is called wicked, as stated (in Exod. 2:13), “so he said to the wicked one, ‘Why would you strike³⁹The midrash understands the verb in accord with post-biblical usage and is stressing the fact that the tense is future. So also Sanh. 58b; Rashi on Exod.2:13. your comrade?’” "Did you strike," is not stated here, but “would you strike.” The one who borrows and does not repay, as stated (in Ps. 37:21), “The wicked person borrows but does not repay.”⁴⁰Avot 2:9. The one who has an insolent face but does not feel shame from someone greater than himself, as stated (Prov. 21:29), “A wicked person puts on a brazen face.” And the one who is the author of dissension, as stated (in Numb. 16:26), “Please move away from the tents of these wicked men.”
Now two [of these traits] were in Dathan and Abiram, [i.e.,] an insolent face and dissension (mhlqt). Mhlqt ("dissension") is interpreted through its letters. M is for marah ("bitter"); h is for haron ("anger"); l is for lokin ("lash"); q is for qelalah ("curse"); and t is for to'evah ("abomination"). But some say [that t stands for] takhlit ("end"), [since dissension] brings annihilation to the world. (Numb. 16:27:) “So they got away from the dwellings of Korah, Dathan and Abiram.” When they saw this, how Israel had moved away from round about them, they came out cursing and blaspheming, as stated (ibid., cont.), “[they] came out standing (rt.: ntsb).” Now [it is stated] elsewhere (in I Sam. 17:16), “Then the Philistine drew near at dawn and in the evening; and he took his stand (rt.: ytsb) for forty days.”⁴¹On Goliath reviling Israel, see I Sam. 17:8-10. Moses began by saying, as it is written (in Numb. 16:28-29), “And Moses said, ‘By this you may know that the Lord has sent me…. If these die like the death of every man.” A parable: To what is the matter comparable? To the shoshbin⁴²I.e., the bridal agent who guarded her interests at the consummation of the marriage. of a king's daughter in whose hands lay the testimonials of her [virginity]. When one of the banqueters stood up before him and cursed the shoshbin and said, “The king's daughter has no virginity”; the shoshbin arose in the presence of the king and said to him, “If you do not have this person brought out in order to execute him in everyone's presence, I shall say, ‘Of course the king's daughter has no virginity.’” Immediately the king said, “It is better for me to kill this person, so that the shoshbin will not give out a bad name concerning my daughter.” Similarly Korah contended with Moses and said, “It was in his own heart and on his own that Moses had said all these things.” He began by saying (in Numb. 16:28-29), “’By this you may know that the Lord has sent me […]. If these die like the death of every man,’ then I also am saying (ibid., cont.), ‘the Lord did not send me,’ and I have spoken from my own heart.”