Numbers 19:5

19:5 Then the heifer must be burned in his sight – its skin, its flesh, its blood, and its offal is to be burned.

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.