Numbers 19:16-18, 20-21

Whoever in the open field touches one who is slain by a sword or who has died, or a bone of a man, or a grave, shall be unclean seven days. ‘And for an unclean person they shall take some of the ashes of the heifer burnt for purification from sin, and running water shall be put on them in a vessel. A clean person shall take hyssop and dip it in the water, sprinkle it on the tent, on all the vessels, on the persons who were there, or on the one who touched a bone, the slain, the dead, or a grave.

‘But the man who is unclean and does not purify himself, that person shall be cut off from among the assembly, because he has defiled the sanctuary of the LORD. The water of purification has not been sprinkled on him; he is unclean. 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.