What is the significanc of the juxtaposition of "Lo Yih'yeh la'Kohanim ha'Levi'im" to the Parshah of kings?
Yerushalmi Sotah, 8:3: It teaches us that a Kohen cannot be annointed as king. 1
This was the sin of the Chashmona'im, and was instrumental in their being wiped out, as the Ramban explains. See also Torah Temimah, note 99, who elaborates.
Why does the Pasuk insert the word "Kol Sheivet Levi"?
Rashi (citing the Sifri 163): It comes to include Kohanim and Levi'im who are Ba'alei Mumin 1 in the preclusion - who do not receive Cheilek ve'Nachalah. 2
Sifri #1 (according to the Vilna Gaon's text): It comes to incorporate Levi'im who are not Kohanim in the preclusion.
Targum Yonasan: 'The Pasuk means 'the Kohanim who are from the tribe of Levi'.
See Torah Temimah, note 1.
The words imply that it is discussing Levi'im, even though blemishes do not disqualify them - Tosefta Chulin 1:16. The Sifri however is presumably, discussing Kohanim, since it states that Ba'al Mumim do not serve, and it cites "Veshereis" (18:7), which the Sifri later expounds with regard to Kohanim. And this is also how the Sifsei Chachamim explains.
What are the "Cheilek" and "Nachalah" that the Kohanim do not receive?
Rashi (citing the Sifri): "Cheilek" refers to the spoils of war, "Nachalah" to a portion of land.
Hadar Zekenim: They do not receive an inheritance by themselves, like the other tribes.
What are "Ishei Hashem" and "Nachalaso" that the Kohanim and the Levi'im do receive?
Rashi: "Ishei Hashem" refers to the Kodshei ha'Mikdash, and "Nachalaso" to Kodshei ha'Gevul - such as T'rumos and Ma'asros.
Targum Yonasan: "Ishei Hashem" refers to the Kodshei ha'Mikdash, and "Nachalaso", to the Arei Miklat. 1
Yerushalmi Chalah, 4:4: "Ishei Hashem" refers to the Kodshei ha'Mikdash, and "Nachalaso", to the Charamim of Karka that are given to the Kohanim - which are given to the Kohanim of that Mishmar, like the Ishei Hashem". 2
