Aaron and his sons held the Aaronic Priesthood, and the Levites were given unto them to minister unto them to keep his charge, the charge of the congregation, to do the service of the tabernacle, keep the instruments of the tabernacle, and the charge of the children of Israel. "And I, behold, I have taken the Levites from among the children of Israel instead of all the firstborn that openeth the matrix among the children of Israel; therefore the Levites shall be mine; because all the firstborn are mine; for on the day that I smote all the firstborn in the land of Egypt I hallowed unto me all the firstborn in Israel, both man and beast: mine they shall be: I am the Lord."--Num. iii, 12, 13. All the firstborn the Lord claimed as belonging to him, because when he destroyed the firstborn of the Egyptians, he spared the firstborn of the Israelites. But the Levites were appointed to fill the place of the firstborn of all Israel, and they were commanded to be numbered, viz., all the males from a month old and upward, to assist Aaron and his sons in the service of the tabernacle; at that time there were twenty-two thousand of them. (Ibid, ver. 39.) "And the Lord spake unto Moses, saying: Take the Levites instead of all the first born among the children of Israel, and the cattle of the Levites instead of their cattle; and the Levites shall be mine: I am the Lord." (ver. 44, 45.) The remainder of the Israelites had to redeem their firstborn, and the money for the redemption was given by Moses to Aaron and his sons according to the word of the Lord. (ver. 50, 51.) They seemed to have been an appendage to the Aaronic Priesthood to assist in the service of the tabernacle and other duties. Aaron and his male descendants were selected for the Priesthood, and the other Levites as assistants, or an appendage. The Levites had forty-eight cities and their suburbs provided for them from among the possessions of the other tribes: First came by lot the children of Aaron: "And the children of Aaron the Priest, which were of the Levites, had by lot out of the tribe of Judah, and out of the tribe of Simeon, and out of the tribe of Benjamin, thirteen cities."--Josh, xxi, 4. (See the whole of the chapter for a division of cities to the remainder of the Levites, or the tribe of Levi, who were thus provided for as distinct from the other tribes.) "All the cities of the Levites within the possession of the children of Israel were forty and eight cities with their suburbs."--Josh, xxi, 41.