The priest shall wash his clothes— See Leviticus 24:23; Leviticus 24:23. Bishop Patrick says, some may think it strange, that the same thing should both cleanse and pollute: but this is agreeable to the notion of all expiatory sacrifices; which, though they purified those for whom they were offered, were themselves impure, because the sins of men were, in a manner, transferred to them.
Related Commentaries of Numbers 19:7
Numbers 19:7
7 Then 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.