Numbers 19:19-20

and the clean person shall sprinkle upon the unclean on the third day, and on the seventh day: and on the seventh day he shall purify him; and he shall wash his clothes, and bathe himself in water, and shall be clean at even. But the man that shall be unclean, and shall not purify himself, that soul shall be cut off from the midst of the assembly, because he hath defiled the sanctuary of Jehovah: the water for impurity hath not been sprinkled upon him; he is unclean.