Numbers 19:20-21

20But a person who is unclean and does not purify himself, that person will be cut off from the assembly because he has defiled the sanctuary of the Lord. The water for impurity has not been sprinkled on him; he is unclean.

21This is a permanent statute for them. The person who sprinkles the water for impurity is to wash his clothes, and whoever touches the water for impurity will be unclean until evening.