For upon this necessary occasion the inferior priests are allowed to come into the holy of holies, which otherwise was peculiar to the high priest, Hebrews 9:7. The covering veil; the second veil; of which see Exodus 26:31, &c. Leviticus 4:6 Hebrews 9:3; where, with the ark was covered while the tabernacle stood, Exodus 40:3. And cover the ark; because the Levites, who were to carry the ark, might neither see nor immediately touch it.
Related Commentaries of Numbers 4:5
Numbers 4:5
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: