Komentarz do Powtórzonego Prawa 18:2

כאשר דבר לו AS HE SPOKE TO HIM i.e., to Aaron [saying],“You shall not inherit in their land… I am your portion [and your inheritance, among the children of Israel].”- (Numbers 18:20)

ונחלה לא יהיה לו, “He shall not have an inheritance.” Rashi, taking his cue from the Sifri, commenting on Exodus 13,5 where only the names of five Canaanite tribes are mentioned, says that all seven tribes were meant. Nachmanides writes that in that verse the reason that only five Canaanite tribes were mentioned is that the territory of those five fell under the heading of “a land flowing with milk and honey,” whereas the territory of the P’rizi and Girgashi, omitted on that occasion, was less fruitful. This is the reason why produce grown on land that used to belong to those two tribes was not subject to the bikkurim legislation, i.e. that the farmer in those lands did not have to bring the first ripe fruit to Jerusalem. If the basic legislation that the priests and Levites had no ancestral share in the land of Israel is repeated here, it was in order to make the point that these Levites also did not have an ancestral share in the lands formerly owned by the P’rizi and Girgashi.

ונחלה לא יהיה לו, “He shall not have an inheritance with Israel.” The word נחלה in verse one refers to distribution of the land of the seven Canaanite tribes being dispossessed in the immediate future, whereas the same word in our verse refers to the land of the remaining three Canaanite tribes, the Kenizi, Keyni, and Kadmoni, which will become part of the land of Israel only in the future.
בקרב אחיו, “among his brothers;” this is a reference to his “full” brothers the other sons of Leah.
ה' הוא נחלתו, “the Lord is his heritage;” Levi was the tenth of the brothers if one counts from the youngest to the oldest something I have elaborated on in Numbers 18,19. This is why this tribe is described as G’d’s heritage, and this is why the tithes are given to this tribe.