Numbers 19:10-12

10The one who gathers the ashes of the heifer 1shall wash his clothes and be unclean until evening; and it shall be a perpetual statute to the sons of Israel and to the alien who sojourns among them.

11‘2The one who touches the corpse of any 3person shall be unclean for seven days. 12That one shall 4purify himself from uncleanness with 5the water on the third day and on the seventh day, and then he will be clean; but if he does not purify himself on the third day and on the seventh day, he will not be clean.