John Gill Commentary Leviticus 14:48

"And if the priest shall come in, and look, and, behold, the plague hath not spread in the house, after the house was plastered; then the priest shall pronounce the house clean, because the plague is healed." — Leviticus 14:48 (ASV)

And if the priest shall come in, and look [upon it]
That is, on the seventh day of the second week of its being shut up:

and, behold, the plague has not spread in the house, after the house
was plastered; (See Gill on Leviticus 14:42):

then the priest shall pronounce the house clean ;
fit to be inhabited, and so no more to be shut up, but free for use as before:

because the plague is healed ;
the infection being wholly removed by taking out the stones, scraping, and plastering the house, and so an entire stop put to the spread of it.