Numbers 1:45-53
English Standard Version
Chapter 1
45So all those listed of the people of Israel, by their fathers ' houses, from twenty years old and upward, every man able to go to war in Israel — 46all those listed were 603,550.
47But the Levites were not listed along with them by their ancestral tribe.
48For the Lord spoke to Moses, saying,
49"Only the tribe of Levi you shall not list, and you shall not take a census of them among the people of Israel.
50But appoint the Levites over the tabernacle of the testimony, and over all its furnishings, and over all that belongs to it. They are to carry the tabernacle and all its furnishings, and they shall take care of it and shall camp around the tabernacle.
51When the tabernacle is to set out, the Levites shall take it down, and when the tabernacle is to be pitched, the Levites shall set it up. And if any outsider comes near, he shall be put to death.
52The people of Israel shall pitch their tents by their companies, each man in his own camp and each man by his own standard.
53But the Levites shall camp around the tabernacle of the testimony, so that there may be no wrath on the congregation of the people of Israel. And the Levites shall keep guard over the tabernacle of the testimony."