"Cursed be their anger, for it was fierce" (Genesis 49:7). At the hour they killed Shechem and all the men of the city, they did not take counsel with their father, and their wrath was cursed exceedingly. Therefore "I will divide them in Jacob and scatter them in Israel" — to raise up from Simeon scribes and teachers in synagogues, and from the tribe of Levi houses of study where they would occupy themselves with Torah. Another explanation: "Simeon and Levi are brothers." And were they not all brothers? Rather, they were brothers in counsel. They took counsel against Shechem and destroyed it, as it is said, "And the two sons of Jacob, Simeon and Levi, took" (Genesis 34:25). And they took counsel against Joseph, for they sought to kill him, as it is said, "And they said to one another, Behold, this dreamer comes; now come, let us kill him" (Genesis 37:19-20). Who were they? If you say Reuben — behold, Reuben sought to save him, as it is said, "And Reuben heard and saved him from their hands." If you say Judah — behold, he said, "What profit is it if we kill our brother" (Genesis 37:26). And if you say the sons of the handmaids — behold, it is already said, "and he was a youth with the sons of Bilhah." Rather, who were they? These are Simeon and Levi, of whom it is written, "Simeon and Levi are brothers." And likewise when they came to Egypt, Joseph said: If I leave Simeon and Levi in one place, they will take counsel and destroy the great metropolis of Egypt. Therefore he separated Simeon from Levi, as it is said, "And he took Simeon from them" (Genesis 42:24). And once he separated them, Levi was left alone, as it is said, "And one opened his sack" (Genesis 42:27) — was there only one? Rather, this is Levi, who was left alone from his pair. At that hour the strength of Levi weakened. Therefore it is said, "Simeon and Levi are brothers."
Why Simeon and Levi Were Scattered and Set Apart
Yalkut Shimoni on Torah 158:1
אָרוּר אַפָּם כִּי עָז. בְּשָׁעָה שֶׁהָרְגוּ שְׁכֶם וְכָל אַנְשֵׁי הָעִיר לֹא נִמְלְכוּ בַּאֲבִיהֶם, וְאָרוּר כַּעְסָם בְּיוֹתֵר, לְפִיכָךְ אֲחַלְּקֵם בְּיַעֲקֹב וַאֲפִיצֵם בְּיִשְׂרָאֵל, לְהַעֲמִיד מִשִּׁמְעוֹן סוֹפְרִים וּמְשַׁנִּים בְּבָתֵּי כְּנֵסִיּוֹת, וּמִשֵּׁבֶט לֵוִי בָּתֵּי מִדְרָשׁוֹת שֶׁיִּהְיוּ עוֹסְקִין בַּתּוֹרָה. דָּבָר אַחֵר, שִׁמְעוֹן וְלֵוִי אַחִים. וְכֻלָּם אֵינָם אַחִים אֶלָּא אַחִים בְּעֵצָה, נָטְלוּ עֵצָה עַל שְׁכֶם וְהֶחְרִיבוּהָ, שֶׁנֶּאֱמַר (בראשית לד, כה) "וַיִּקְחוּ שְׁנֵי בְנֵי יַעֲקֹב שִׁמְעוֹן וְלֵוִי". וְהֵם נָטְלוּ עֵצָה עַל יוֹסֵף, שֶׁבִּקְּשׁוּ לְהָרְגוֹ, שֶׁנֶּאֱמַר (בראשית לז, יט כ) "וַיֹאמְרוּ אִישׁ אֶל אָחִיו הִנֵּה בַּעַל הַחֲלֹמוֹת הַלָּזֶה בָּא וְעַתָּה לְכוּ וְנַהֲרְגֵהוּ", מִי הָיוּ, אִם תֹּאמַר רְאוּבֵן, הֲרֵי רְאוּבֵן בִּקֵשׁ לְהַצִּילוֹ, שֶׁנֶּאֱמַר "וַיִּשְׁמַע רְאוּבֵן וַיַּצִּלֵהוּ מִיָּדָם", אִם תֹּאמַר יְהוּדָה, הֲרֵי אָמַר (שם כו) "מַה בֶּצַע כִּי נַהֲרֹג אֶת אָחִינוּ", וְאִם תֹּאמַר בְּנֵי הַשְּׁפָחוֹת, הֲרֵי כְּבָר נֶאֱמַר, "וְהוּא נַעַר אֶת בְּנֵי בִלְהָה", אֶלָּא מִי הֵם, זֶה שִׁמְעוֹן וְלֵוִי, דִּכְתִיב בָּהֶם שִׁמְעוֹן וְלֵוִי אַחִים. וְכֵן כְּשֶׁבָּאוּ לְמִצְרַיִם אָמַר יוֹסֵף, אִם אֲנִי מַנִּיחַ לְשִׁמְעוֹן וְלֵוִי בְּמָקוֹם אֶחָד הֵן נוֹטְלִין עֵצָה וּמַחְרִיבִין כְּרַךְ גָּדוֹל שֶׁל מִצְרַיִם, לְפִיכָךְ הִפְרִיש שִׁמְעוֹן מִלֵּוִי, שֶׁנֶּאֱמַר (שם מב, כד) "וַיִּקַּח מֵאִתָּם אֶת שִׁמְעוֹן", וְכֵיוָן שֶׁהִפְרִישׁ אוֹתָם נַעֲשָׂה לֵוִי יְחִידִי, שֶׁנֶּאֱמַר (שם מב, כז) "וַיִּפְתַּח הָאֶחָד אֶת שַׂקּוֹ", וְכִי אֶחָד הָיָה אֶלָּא זֶה לֵוִי הַנִּשְׁאָר יְחִידִי מִזּוּגוֹ. בְּאוֹתָהּ שָׁעָה תָּשַׁשׁ כֹּחוֹ שֶׁל לֵוִי. לְכָךְ נֶאֱמַר שִׁמְעוֹן וְלֵוִי אַחִים.