(Devarim 21:5) "Then there shall draw near the Cohanim, the sons of Levi": What is the intent of this? (i.e., Don't we know that the Cohanim are the sons of Levi?) — Because it is written (Ibid.) "for them did the L-rd your G-d choose to serve Him," I might think that only unblemished Cohanim are eligible (for this rite); it is, therefore, written "the sons of Levi" — to teach that blemished Cohanim are eligible for the breaking of the neck of the heifer.
"to serve Him and to pronounce the benediction in the name of the L-rd": The (priestly) benediction is being likened to the (priestly) service. Just as the latter is performed, standing, so, the former.
"and by their word shall every contention and every plague-spot be (ruled upon."): Contentions are being compared to plague-spots, and plague-spots to contentions. Just as plague-spots are (ruled upon) only in the daytime, so, contentions. And just as contentions are not (ruled upon) by kin, so, plague-spots. If so, why not say: Just as contentions require three (judges), so, plague-spots.
And it would follow a fortiori, viz.: If his money requires three, how much more so, his body! It is, therefore, written (re plague-spots, Vayikra 13:3) "… or to one of his sons, the Cohanim" — One Cohein rules on a plague-spot.
(דברים כא ה) וְנִגְּשׁוּ הַכֹּהֲנִים בְּנֵי לֵוִי, מִכְּלָל שֶׁנֶּאֱמַר (דברים יח ז) ״וְשֵׁרֵת בְּשֵׁם ה׳ אֱלֹהָיו״, אֵין לִי אֶלָּא תְמִימִים, בַּעֲלֵי מוּמִים מִנַּיִן? תַּלְמוּד לוֹמַר בְּנֵי לֵוִי. כִּי בָם בָּחַר ה׳ אֱלֹהֶיךָ [לְשָׁרְתוֹ וּלְבָרֵךְ בִּשְׁמוֹ], מַגִּיד שֶׁאֵין בִּרְכַּת כֹּהֲנִים כְּשֵׁרָה בְּבַעֲלֵי מוּמִים.
(Devarim 21:5) "Then there shall draw near the Cohanim, the sons of Levi": What is the intent of this? (i.e., Don't we know that the Cohanim are the sons of Levi?) — Because it is written (Ibid.) "for them did the L-rd your G-d choose to serve Him," I might think that only unblemished Cohanim are eligible (for this rite); it is, therefore, written "the sons of Levi" — to teach that blemished Cohanim are eligible for the breaking of the neck of the heifer.
לְשָׁרְתוֹ וּלְבָרֵךְ בְּשֵׁם ה׳, מַקִּישׁ בְּרָכָה לְשֵׁרוּת: מַה שֵּׁרוּת בַּעֲמִידָה – אַף בְּרָכָה בַּעֲמִידָה.
"to serve Him and to pronounce the benediction in the name of the L-rd": The (priestly) benediction is being likened to the (priestly) service. Just as the latter is performed, standing, so, the former.
וְעַל פִּיהֶם יִהְיֶה כָּל רִיב וְכָל נָגַע, מַקִּישׁ רִיבִים לִנְגָעִים: מַה נְּגָעִים בַּיּוֹם – אַף רִיבִים בַּיּוֹם, מַה רִיבִים שֶׁלֹּא בִּקְרוֹבִים – אַף נְגָעִים שֶׁלֹּא בִּקְרוֹבִים.
"and by their word shall every contention and every plague-spot be (ruled upon."): Contentions are being compared to plague-spots, and plague-spots to contentions. Just as plague-spots are (ruled upon) only in the daytime, so, contentions. And just as contentions are not (ruled upon) by kin, so, plague-spots. If so, why not say: Just as contentions require three (judges), so, plague-spots.
אוֹ, מָה רִיבִים בִּשְׁלֹשָׁה אַף נְגָעִים בִּשְׁלֹשָׁה? וְדִין הוּא, אִם מָמוֹנוֹ בִּשְׁלֹשָׁה גּוּפוֹ לֹא יְהֵא בִּשְׁלֹשָׁה? תַּלְמוּד לוֹמַר (ויקרא יג ב): ״אוֹ אֶל אַחַד מִבָּנָיו הַכֹּהֲנִים״, לְלַמֶּדְךָ שֶׁכֹּהֵן אֶחָד רוֹאֶה אֶת הַנְּגָעִים!
And it would follow a fortiori, viz.: If his money requires three, how much more so, his body! It is, therefore, written (re plague-spots, Vayikra 13:3) "… or to one of his sons, the Cohanim" — One Cohein rules on a plague-spot.