Leviticus 6:10-11

10The priest is to put on 1his linen robe, and he shall put on undergarments next to his flesh; and he shall take up the 2ashes to which the fire 3reduces the burnt offering on the altar and place them beside the altar.

11Then he shall take off his garments and put on other garments, and carry the 4ashes outside the camp to a clean place.