Reference

Leviticus 14:39

And the priest shall come again the seventh day, and shall look: and, behold, if the plague be spread in the walls of the house;
37

And he shall look on the plague, and, behold, if the plague be in the walls of the house with hollow strakes, greenish or reddish, which in sight are lower than the wall;

38

Then the priest shall go out of the house to the door of the house, and shut up the house seven days:

39

And the priest shall come again the seventh day, and shall look: and, behold, if the plague be spread in the walls of the house;

40

Then the priest shall command that they take away the stones in which the plague is, and they shall cast them into an unclean place without the city:

41

And he shall cause the house to be scraped within round about, and they shall pour out the dust that they scrape off without the city into an unclean place:

Counter-Arguments

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

Seventh-Day Sabbath

The verse refers to "the seventh day" as a point in a sequence of days for inspection, not as a day of rest or a Sabbath. There is no mention of the Sabbath or any concept of rest in this passage.

Pre-Law Clean/Unclean Distinction

This verse is found within the book of Leviticus, which details the Mosaic Law given at Sinai, and therefore describes a distinction that is part of that law, not one existing prior to it. The verse itself does not contain any temporal indicators suggesting the described clean/unclean distinction predates the giving of the Law.