民數記 19:19

第三天和第七天，潔淨的人要灑水在不潔淨的人身上，第七天就使他成為潔淨。那人要洗衣服，用水洗澡，到晚上就潔淨了。

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 himself, and wash his clothes, and bathe himself in water, and shall be clean at even.