Tafsiran Bilangan 8:6: Rashi, Kli Yakar, Or HaChaim & Tur HaArokh

קח את הלוים means, win them over with fine words: “Happy are ye that ye are privileged to be servants of the Omnipresent!” (cf. Rashi on Leviticus 8:2.)

Take the Levites: Sometimes it mentions the language of “taking” and sometimes the language of “giving,” and this matter requires explanation. Also, what is the duplication in saying for they are given, given to Me, and afterward He contradicts Himself by saying I have taken them for Myself. It appears that due to the necessity of these questions, the Tanchuma (Behaalotcha 8) concludes Take the Levites — take them for My name, for a position of authority. And with this, all the questions are resolved, because we find the language of “taking” regarding the exchange of the firstborn, as it is written instead of every firstborn that opens the womb… I have taken them for Myself.

קח את הלוים, "Take the Levites! etc." Rashi explains that the word "take!" means by means of words. Apparently Rashi means that Moses was to separate the Levites from the camps of the Israelites and make a separate camp for them seeing the Levites had to guard their ritual purity more than ordinary Israelites. The proof is to be found in the words וטהרת אותם, "and purify them!" Clearly what concerns the Torah at this point is the need for the Levites to maintain a state of ritual purity.