Numbers 4:4-6

Amplified Bible

⁴ This is the work and responsibility of the sons of Kohath in the Tent of Meeting (tabernacle): the most holy things.

⁵ “When the camp prepares to move out, Aaron and his sons shall come into the sanctuary and take down ^[a]the veil (curtain) screening off the Holy of Holies, and cover the ark of the testimony with it; ⁶ and they shall put on it a covering of ^[b]porpoise skin (fine leather), and shall spread over that a cloth of pure blue, and shall insert the carrying poles of the ark.