Numbers 3:6. Bring the tribe of Levi near, and present them before Aaron the priest, that they may minister unto him.
The family of Aaron were set apart especially to the duties of the priesthood. The rest of the tribe of Levi were consecrated to special services in connection with the worship of Jehovah. Each of the three families had its particular duties assigned. The Kohathites had charge of the sacred utensils of the Tabernacle. They saw that they were properly removed when on the march, and that they were put into their appropriate places when the encampment was again fixed (Num. 4:4-15). The Gershonites took care of the hangings and curtains of the Tabernacle (Num 4:21-28). The Merarites were required to look after the boards, sockets, pillars, pins, and cords of the Tabernacle (Num. 4:29-33). Moses also gave the Levites judicial authority (Deut. 17:8-12) and made them keepers of the book of the law (Deut. 31:9,25-26). After the temple was built they acted as porters, musicians, and assistants to the priests.
The first Levites who were appointed began their service at thirty years of age (Num. 4:23,30,35), but it was ordered that after that the age for commencing should be twenty-five years (Num. 8:24). In David’s time they began serving at twenty (1 Chron. 23:24-27). They were released from all obligation to serve when they became fifty years old (Num. 8:25).
Forty-eight cities were set apart for their residence in the Land of Promise. Six of these were also cities of refuge, and thirteen of them they shared with the priests (Num. 35:1-8; Josh. 21:13-19; 1 Chron. 6:54-60).