Numbers 8:24

This is the [ordinance] for the Levites; From five and twenty years old and upward, they shall go in to minister in the tabernacle of witness.

This is it that belongeth unto the Levites: from twenty and five years old and upward they shall go in to wait upon the service of the tabernacle of the congregation:

“This is what is assigned to the Levites: from twenty-five years old and upward they shall go in to wait on the service in the work of the Tent of Meeting;