1)
What is the difference between "Vehivdalta es ha'Levi'im" and "Vehayu Li ha'Levi'im"?
1.
Seforno: "Vehivdalta es ha'Levi'im" refers to the way the Levi'im encamped; "Vehayu Li ha'Levi'im", to their designation of them and their descendents to serve Hashem (in the Mishkan and in the Beis-Hamikdash).
2.
Oznayim la'orah (citing Vayikra Rabah): "Vahayu Li ha'Levi'im" means forever - because that is always wht the word "Li" implies.
