Numbers 4:3-5

American Standard Version

³ from thirty years old and upward even until fifty years old, all that enter upon the ^[a]service, to do the work in the tent of meeting. ⁴ This is the ^[b]service of the sons of Kohath in the tent of meeting, about the most holy things: ⁵ when the camp setteth forward, Aaron shall go in, and his sons, and they shall take down the veil of the screen, and cover the ark of the testimony with it,