Numbers 19:5-7

⁵And one shall burn the heifer before his eyes; its skin and its flesh, and its blood, with its dung, shall he burn.

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

⁷And the priest shall wash his garments, and he shall bathe his flesh in water, and afterwards he shall come into the camp; and the priest shall be unclean until the even;