Ezekiel 44:25-27

They shall not defile themselves by going near to a dead person. However, for father or mother, for son or daughter, for brother or unmarried sister they may defile themselves. After he has become clean, they shall count seven days for him. And on the day that he goes into the Holy Place, into the inner court, to minister in the Holy Place, he shall offer his sin offering, declares the Lord GOD.