Reference

Numbers 19:21

And it shall be a perpetual statute unto them, that he that sprinkleth the water of separation shall wash his clothes; and he that toucheth the water of separation shall be unclean until even.
19

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.

20

But the man that shall be unclean, and shall not purify himself, that soul shall be cut off from among the congregation, because he hath defiled the sanctuary of the Lord: the water of separation hath not been sprinkled upon him; he is unclean.

21

And it shall be a perpetual statute unto them, that he that sprinkleth the water of separation shall wash his clothes; and he that toucheth the water of separation shall be unclean until even.

22

And whatsoever the unclean person toucheth shall be unclean; and the soul that toucheth it shall be unclean until even.

Counter-Arguments

The strongest case that this verse does not belong in this theme.

Symbolic / Spiritual Interpretation

The verse explicitly deals with ritual purity and impurity within the Levitical system, not directly with spiritual purity or moral holiness. The "water of separation" is a physical substance used in a specific ritual for physical purification from corpse defilement. While ritual purity can have symbolic undertones, the primary and immediate meaning here is literal ritual status. The text is prescriptive for a physical action and its immediate physical consequence (uncleanliness until evening),