Ezekiel 44:25-27

25A priest must not go near to a dead person. It would make him unclean. But if the dead person is his father, his mother, his son, his daughter, his brother or his sister who has not married, he may go near them. It makes him unclean but he may do that.

26After this, he must make himself clean. Then he must wait seven days.

27Then he can go into the inside yard of the temple to serve me there. On the day that he goes back there, he must make a sin offering for himself. That is what the Almighty Lord says.