חמשת מלכי מדין. וְכִי אֵינִי רוֹאֶה שֶׁחֲמִשָּׁה מָנָה הַכָּתוּב? לָמָּה הֻזְקַק לוֹמַר חֲמֵשֶׁת? אֶלָּא לְלַמֶּדְךָ שֶׁשָּׁווּ כֻלָּם בָּעֵצָה וְהֻשְׁווּ כֻלָּם בַּפֻּרְעָנוּת (שם); בִּלְעָם הָלַךְ שָׁם לִטֹּל שְׂכַר עֶשְׂרִים וְאַרְבָּעָה אֶלֶף שֶׁהִפִּיל מִיִּשְׂרָאֵל בַּעֲצָתוֹ, וְיָצָא מִמִּדְיָן לִקְרַאת יִשְׂרָאֵל וּמַשִּׂיאָן עֵצָה רָעָה — אָמַר לָהֶם אִם כְּשֶׁהֱיִיתֶם שִׁשִּׁים רִבּוֹא לֹא יְכָלְתֶּם לָהֶם, וְעַכְשָׁיו בְּי"ב אֶלֶף אַתֶּם בָּאִים לְהִלָּחֵם? — נָתְנוּ לוֹ שְׂכָרוֹ מִשָּׁלֵם וְלֹא קִפְּחוּהוּ (ספרי): חמשת מלכי מדין THE FIVE KINGS OF MIDIAN — But can I not see that Scripture has enumerated five; why, then, does it feel compelled to say that there were five? But it is to tell you that even as they had all been alike in the plot, so, too, they were treated alike in the punishment that befell them (cf. Rashi on Genesis 25:22, where, as here, the total of the names mentioned is stated) (Sifrei Bamidbar 157:5). — Balaam had gone there to receive the reward for the 24,000 whom he had made to fall of Israel through his counsel and now also he left Midian to meet Israel and gave them bad advice: viz., he said to them, “If, when you were 600,000 you were unable to overcome them, now you come to war against them with 12,000?” They gave him his full reward and did not stint it (they slew him) (Sifrei Bamidbar 157:5).
בחרב. הוּא בָא עַל יִשְׂרָאֵל וְהֶחֱלִיף אֻמָּנוּתוֹ בְּאֻמָּנוּתָם, שֶׁאֵין נוֹצְחִים אֶלָּא בְּפִיהֶם וְעַל יְדֵי תְפִלָּה וּבַקָּשָׁה, וּבָא הוּא וְתָפַשׂ אֻמָּנוּתָם לְקַלְּלָם בְּפִיו, אַף הֵם בָּאוּ עָלָיו וְהֶחֱלִיפוּ אֻמָּנוּתָם בְּאֻמָּנוּת הָאֻמּוֹת שֶׁבָּאִין בַּחֶרֶב, שֶׁנֶּאֱמַר "וְעַל חַרְבְּךָ תִחְיֶה" (בראשית כ"ז): בחרב [BALAAM ALSO … THEY SLEW] WITH THE SWORD — He came against Israel exchanging his metier (the sword) for their metier (the mouth), for they conquer only through their mouth — through prayer and petition, and he came and availed himself of their craft to curse them with his mouth. They, therefore, also came against him and exchanged their craft for the craft of the heathen peoples who come with the sword, as it is said, (Genesis 27:40) “And by thy sword shalt thou live” (cf. Rashi on Numbers 22:23).