Numbers 19:8-10

New Revised Standard Version, Anglicised

⁸ The one who burns the heifer^[a] shall wash his clothes in water and bathe his body in water; he shall remain unclean until evening. ⁹ Then someone who is clean shall gather up the ashes of the heifer, and deposit them outside the camp in a clean place; and they shall be kept for the congregation of the Israelites for the water for cleansing. It is a purification-offering. ¹⁰ The one who gathers the ashes of the heifer shall wash his clothes and be unclean until evening.

This shall be a perpetual statute for the Israelites and for the alien residing among them.