Numbers 19:7, 8, 21

After that, the priest must wash his clothes and bathe himself with water. He may then come into the camp, but he will be ceremonially unclean till evening.

The man who burns it must also wash his clothes and bathe with water, and he too will be unclean till evening.

This is a lasting ordinance for them. “The man who sprinkles the water of cleansing must also wash his clothes, and anyone who touches the water of cleansing will be unclean till evening.