Ezekiel 44:25-27

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. After he is cleansed, seven days shall elapse for him. On the day that he goes into the sanctuary, into the inner court to minister in the sanctuary, he shall offer his sin offering,” declares the Lord GOD.