Numbers 19:7-8, 21

Then the priest shall wash his clothes, he shall bathe in water, and afterward he shall come into the camp; the priest shall be unclean until evening. And the one who burns it shall wash his clothes in water, bathe in water, and shall be unclean until evening.

It shall be a perpetual statute for them. He who sprinkles the water of purification shall wash his clothes; and he who touches the water of purification shall be unclean until evening.