Numbers 19:7-8

19:7 Then the priest must wash his clothes and bathe himself in water, and afterward he may come into the camp, but the priest will be ceremonially unclean until evening. 19:8 The one who burns it must wash his clothes in water and bathe himself in water. He will be ceremonially unclean until evening.

Numbers 19:10

19:10 The one who gathers the ashes of the heifer must wash his clothes and be ceremonially unclean until evening. This will be a permanent ordinance both for the Israelites and the resident foreigner who lives among them.

Numbers 19:19

19:19 And the clean person must sprinkle the unclean on the third day and on the seventh day; and on the seventh day he must purify him, and then he must wash his clothes, and bathe in water, and he will be clean in the evening.