Numbers 19:17-18

“So you must use the ashes from the burnt offering to make that person clean again. Pour fresh water over the ashes into a jar. A clean person must take a hyssop branch and dip it into the water, and then he must sprinkle it over the tent and all its objects. He must also sprinkle the people who were there, as well as anyone who touched a bone, or the body of someone who was killed, or a dead person, or a grave.