He must purify himself with the water on the third day and on the seventh day; then he will be clean. But if he does not purify himself on the third and seventh days, he will not be clean.
Jewish Publication Society of America Version (JPS1917) - Numbers 19:12 >the same shall purify himself therewith on the third day and on the seventh day, and he shall be clean; but if he purify not himself the third day and the seventh day, he shall not be clean.