Numbers 19:20-21

But if those who are unclean do not purify themselves, they must be cut off from the community, because they have defiled the sanctuary of the Lord. The water of cleansing has not been sprinkled on them, and they are unclean. This is a lasting ordinance for them. “The man who sprinkles the water of cleansing must also wash his clothes, and anyone who touches the water of cleansing will be unclean till evening.