Numbers 19:17-21

17“To remove the defilement, put some of the ashes from the burnt purification offering in a jar, and pour fresh water over them.

18Then someone who is ceremonially clean must take a hyssop branch and dip it into the water. That person must sprinkle the water on the tent, on all the furnishings in the tent, and on the people who were in the tent; also on the person who touched a human bone, or touched someone who was killed or who died naturally, or touched a grave.

19On the third and seventh days the person who is ceremonially clean must sprinkle the water on those who are defiled. Then on the seventh day the people being cleansed must wash their clothes and bathe themselves, and that evening they will be cleansed of their defilement.

20“But those who become defiled and do not purify themselves will be cut off from the community, for they have defiled the sanctuary of the Lord. Since the water of purification has not been sprinkled on them, they remain defiled.

21This is a permanent law for the people. Those who sprinkle the water of purification must afterward wash their clothes, and anyone who then touches the water used for purification will remain defiled until evening.