Numbers 19:5-7

⁵And they shall burn her to ashes before him; and her skin and her flesh and her blood, with her dung, shall be consumed.

⁶And the priest shall take cedar wood and hyssop and scarlet wool, and they shall cast them into the midst of the burning of the heifer.

⁷And the priest shall wash his garments, and bathe his body in water, and afterwards he shall go into the camp, and the priest shall be unclean till evening.