Leviticus 14:37

If the leprous spot appeared in "greenish or reddish depressions, which looked deeper than the wall," the priest was to shut up the house for seven days. If after that time he found that the mole had spread on the walls, he was to break out the stones upon which it appeared, and remove them to an unclean place outside the town, and to scrape the house all round inside, and throw the dust that was scraped off into an unclean place outside the town. He was then to put other stones in their place, and plaster the house with fresh mortar.

The former chapter directed the priests how to convict a leper of ceremonial uncleanness. No prescriptions are given for his cure; but, when God had cured him, the priests are in this chapter directed how to cleanse him. The remedy here is only adapted to the ceremonial part of his disease; but the authority Christ gave to his ministers was to cure the lepers, and so to cleanse them. We have here, I. The solemn declaration of the leper's being clean, with the significant ceremony attending it (Lev 14:1-9). II. The sacrifices which he was to offer to God eight days after (v. 10-32). III. The management of a house in which appeared signs of a leprosy (v. 33-53). And the conclusion and summary of this whole matter (Lev 14:54, etc.).

14:37 If the mildew extended deeper than the wall’s surface it was more serious than if it were just on the surface. The same idea was expressed by “more than skin-deep” in the examination of infected individuals (see study note on 13:3).