Numbers 4:4-6

King James Version

⁴ This shall be the service of the sons of Kohath in the tabernacle of the congregation, about the most holy things:

⁵ And when the camp setteth forward, Aaron shall come, and his sons, and they shall take down the covering vail, and cover the ark of testimony with it:

⁶ And shall put thereon the covering of badgers' skins, and shall spread over it a cloth wholly of blue, and shall put in the staves thereof.