Leviticus 14:44
Then the priest shall come and look, and, behold, if the plague be spread in the house, it is a fretting leprosy in the house: it is unclean.
Cross-references
Leviticus 13:51
Historical context
In Leviticus 13:51, the same spreading test applies to garments — consistent principle for uncleanness.
Leviticus 13:52
Parallel
In Leviticus 13:52, the same logic applies to a leprous garment: persistent plague after washing requires burning. Both demand destruction of the contaminated item.