Leviticus 14:44

Then the priest shall come and look ,.... On the seventh day of the second week; though, according to Maimonides F15 Hilchot Tumaat Tzarat, c. 15. sect. 1, 2. , this was at the end of the third seven day, or on the nineteenth day from his first inspection into it; the seventh day being reckoned for the last of the first week, and the first of the second, and so on:

and, behold, if the plague be spread in the house ; after all the above precaution is taken:

it is a fretting leprosy in the house ; like that in the garment; see Gill on Leviticus 13:51 ,

it is unclean ; and so not to be inhabited.