Matthew Poole and continuators on Leviticus 14:37

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:

This was an extraordinary judgment of God peculiar to this people, either as a punishment of their sins, which were much more sinful and inexcusable than the sins of other nations, or as a special mean and help to Repentance, which God afforded to them above other people; or as a document of the mischievous nature of sin, typified by leprosie, which did not onely destroy persons, but their habitations also: see Zech. 5. 4.

Such as were in the bodies of leprous persons, Levit. 13. 3.