To wait upon the service.--Literally, to war the warfare, or to serve the (military) service. Similarly, in the following verse, he shall return from the warfare of the service.
from twenty and five years old and upward, they shall go in to wait upon the service of the tabernacle of the congregation; in Numbers 4:3; the time for the Levites entering on the work of the tabernacle is fixed to thirty years and upward, which Jarchi reconciles thus; at twenty five years old the Levite goes in to learn the rites of service, and he learns five years, and when thirty years of age he services; the same is observed by others (w); but what Aben Ezra proposes seems much better; at thirty years of age a Levite entered into the service of bearing and carrying burdens; and at twenty five years of age he entered into the service of the tent or tabernacle, where he was employed in lighter service, such as opening and shutting the doors of the sanctuary, keeping out strangers and unclean persons, and singing the songs of the sanctuary; but was not concerned till thirty years of age in carrying the vessels of the sanctuary on the shoulders, as the Kohathites; or in taking down and setting up the tabernacle, loading and unloading the wagons, as the Gershonites and Merarites; which is the business assigned unto them, and spoken of in Numbers 4:22, where the age of thirty years, and upward, is mentioned, as the time of their entrance on it, Numbers 4:23.
(w) Ben Gersom in loc. Bartenora in Pirke Abot, c. 5. sect. 21.