Numbers 19:7-8, 19

The priest shall then wash his clothes and bathe his body in water, and afterward come into the camp, but the priest shall be unclean until evening. The one who burns it shall also wash his clothes in water and bathe his body in water, and shall be unclean until evening.

Then the clean person shall sprinkle on the unclean on the third day and on the seventh day; and on the seventh day he shall purify him from uncleanness, and he shall wash his clothes and bathe himself in water and shall be clean by evening.