Ezekiel 44:23-27

Moreover, they shall teach My people the difference between the holy and the common, and teach them to distinguish between the unclean and the clean.

In a dispute they shall take their stand to judge; they shall judge it according to My ordinances. They shall also keep My laws and My statutes in all My appointed feasts, and sanctify My Sabbaths.

They shall not go to a dead person to defile themselves; however, for father, for mother, for son, for daughter, for brother, or for a sister who has not had a husband, they may defile themselves.

And after he is cleansed, seven days shall elapse for him.

On the day that he goes into the sanctuary, to the inner courtyard to minister in the sanctuary, he shall offer his sin offering,” declares the Lord God.