Leviticus 16:27-28

And the bullock for the sin offering, and the goat for the sin offering, whose blood was brought in to make atonement in the holy place, shall one carry forth without the camp; and they shall burn in the fire their skins, and their flesh, and their dung.

And he that burneth them shall wash his clothes, and bathe his flesh in water, and afterward he shall come into the camp.