Leviticus 16:33-34

Common English Bible

³³ He will reconcile the holiest part of the sanctuary and will do the same for the meeting tent and the altar. He will make reconciliation for the priests and for all the people of the assembly. ³⁴ This will be a permanent rule for you, in order to make reconciliation for the Israelites from all their sins once a year.

It was done just as the Lord commanded Moses.