וְהֵנִיף֩ אַהֲרֹ֨ן אֶת־הַלְוִיִּ֤ם תְּנוּפָה֙ לִפְנֵ֣י יְהוָ֔ה מֵאֵ֖ת בְּנֵ֣י יִשְׂרָאֵ֑ל וְהָי֕וּ לַעֲבֹ֖ד אֶת־עֲבֹדַ֥ת יְהוָֽה׃
און אַהרן זאָל אױפֿהײבן די לוִיִים אַן אױפֿהײבונג פֿאַר גאָט פֿון די קינדער פֿון ישׂראל, כּדי זײ זאָלן זײַן אױף צו דינען דעם דינסט פֿון גאָט.
Rashi
והניף אהרן את הלוים תנופה AND AARON SHALL MAKE A WAVING WITH THE LEVITES — just as the guilt offering of the leper (to whom the Levites are compared in some respect; cf. Rashi on v. 7) required waving whilst alive. — Three times is the command of waving the Levites mentioned in this section (vv. 11, 13, 15): the first refers to the sons of Kohath; therefore (because it is they who are referred to) Scripture adds with regard to them, “that they may execute the service of the Lord” — for it was upon them (the sons of Kohath) that the service of the most holy objects: the Ark, the table, etc., devolved. The second refers to the sons of Gershon, and therefore Scripture adds with regard to them, “a waving for the Lord”, for upon them devolved the service of the holy (though not the most holy) objects: the hangings and the catches which were visible in the Holy of Holies. The third refers to the sons of Merari.
Siftei Chakhamim
Requires waving. A leper is termed “dead” as it says at the end of the Parshah “please, let her not be like the dead” (12:12) and the Levites were as an atonement for the firstborn who worshiped idols, which is termed “sacrifices of the dead.” Therefore, the Levites required “live waving” like the guilt-offering of a leper. Furthermore, the waving of the Levites would only be possible while they were alive.
Rav Hirsch
V. 11. והניף אהרן וגו׳. Dreimal kommt in diesem Akt, der Levitenweihe תנופה vor: Verse 11, 13 und 15. Die Bedeutung der תנופה-Handlung als Ausdruck der "Widmung" eines Objektes, des Zuwendens, ist bekannt. Die Weihe der Leviten vollzieht sich nun in einer dreifachen Widmung, wie diese in Versen 16-19 erläutert wird: Israel widmet sie Gott, Gott widmet sie Aharon und seinen Söhnen, Aharon und seine Söhne widmen sie dem Dienste des Heiligtums. Es ist daher im Namen Gottes, im Namen der Nation und im Namen Aharons, daß die Leviten ihre Stellung innenehmen und ihren Beruf zu erfüllen haben, und diese drei Beziehungen ihres künftigen Berufes werden durch die drei תנופות zum Bewusstsein gebracht. Hier zuerst die Übergabe der Leviten von Israel an Gott: והניף וגו׳ לפני ד׳ מאת בני ישראל והיו לעבד את עבדת ד׳.