Ezekiel 44:25-27

25And they shall come at no dead person to defile themselves: but for father, or for mother, or for son, or for daughter, for brother, or for sister that hath had no husband, they may defile themselves.

26And after he is cleansed, they shall reckon unto him seven days.

27And in the day that he goeth into the sanctuary, unto the inner court, to minister in the sanctuary, he shall offer his sin offering, saith the Lord God.