Numbers 19:10-12

10And he that gathereth the ashes of the heifer shall wash his clothes, and be unclean until the evening: and it shall be to the children of Israel, and to the stranger that sojourneth among them, for a statute for ever.

11He that toucheth the dead body of any man shall be unclean seven days.1 12He shall purify himself with it on the third day, and on the seventh day he shall be clean: but if he shall not purify himself the third day, then the seventh day he shall not be clean.