"in the midst of his brothers": This is the inheritance of the five (peoples — Canaani, Chitti, Emori, Chivi, Yevussi).
"The L-rd is his inheritance as He spoke to him": This is the rationale of the foregoing.
(Devarim 18:3) "And this shall be the judgment of the Cohanim": We are hereby taught that the priestly gifts (shoulder, cheeks, and maw) are "law" (to the end of extracting them by court order from a thief who stole them from a Cohein who had acquired them from hefker [ownerless property]).