GOD'S WORD® Translation
The unclean person must use this water on the third day and the seventh day to take away his sin. Then he will be clean. But if he doesn't use this water on the third day and the seventh day, he will not be clean.

American Standard Version
the same shall purify himself therewith on the third day, and on the seventh day he shall be clean: but if he purify not himself the third day, then the seventh day he shall not be clean.

Berean Study Bible
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.

Douay-Rheims Bible
Shall be sprinkled with this water on the third day, and on the seventh, and so shall be cleansed. If he were not sprinkled on the third day, he cannot be cleansed on the seventh.

English Revised Version
the same shall purify himself therewith on the third day, and on the seventh day he shall be clean: but if he purify not himself the third day, then the seventh day he shall not be clean.

King James Bible
He shall purify himself with it on the third day, and on the seventh day he shall be clean: but if he purify not himself the third day, then the seventh day he shall not be clean.

World English Bible
the same shall purify himself with water on the third day, and on the seventh day he shall be clean: but if he doesn't purify himself the third day, then the seventh day he shall not be clean.

Young's Literal Translation
he doth cleanse himself for it on the third day, and on the seventh day he is clean; and if he cleanse not himself on the third day, then on the seventh day he is not clean.

Numbers 19:12 Additional Translations ...