TSK · Numbers 10:21

And when the tabernacle setteth forward, the Levites shall take it down: and when the tabernacle is to be pitched, the Levites shall set it up: and the stranger that cometh nigh shall be put to death.

And of Kohath [was] the family of the Amramites, and the family of the Izeharites, and the family of the Hebronites, and the family of the Uzzielites: these [are] the families of the Kohathites.

And when Aaron and his sons have made an end of covering the sanctuary, and all the vessels of the sanctuary, as the camp is to set forward; after that, the sons of Kohath shall come to bear [it]: but they shall not touch [any] holy thing, lest they die. These [things are] the burden of the sons of Kohath in the tabernacle of the congregation.

But unto the sons of Kohath he gave none: because the service of the sanctuary belonging unto them [was that] they should bear upon their shoulders.

Then David said, None ought to carry the ark of God but the Levites: for them hath the LORD chosen to carry the ark of God, and to minister unto him for ever.