Numbers 19:5-7

⁵and one shall burn the heifer in his sight; her skin, and her flesh, and her blood, with her dung, shall he burn:

⁶and the priest shall take cedar wood, and hyssop, and scarlet, and cast it into the midst of the burning of the heifer.

⁷Then the priest shall wash his clothes, and he shall bathe his flesh in water, and afterward he shall come into the camp, and the priest shall be unclean until the even.