Chabad.org — English translation + Rashi
Torah Temimah (Sifrei / Chullin context): after fifty the Levite continues to serve his brothers by residual duties; “shareit” marks the lighter service.
English: “And he shall serve his brothers in the Tent of Meeting to keep the charge, but he shall not do the work” — teaching that he returns to gate-locking.
Limitation of retirement — the verse distinguishes full labor from residual supportive service.
Retirement from the heavy burden does not mean total exclusion; the elder Levite remains integrated through lighter, supportive roles.