Aliya Summary: The exact prescribed initiation procedure is followed, and the Levites are consecrated to G‑d — in stead of the firstborn who lost their hallowed status when they participated in the sin of the Golden Calf. Towards the end of this Aliya we learn the Levite service age-requirements and retirement age.
From age 25 until 50, the Levi was eligible for Mishkan service. From 25-30 the Levi studied and trained for Temple service, at 30 he began serving. Age 50 was the retirement age for the “carrying chores”, but the singing and guarding functions of the Levi continued beyond that age.