Charles Ellicott 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)

The plague has not spread. —If at the end of the second week’s quarantine the disease has not spread, having been checked by the means prescribed in Leviticus 14:42-43, the priest is to declare it clean, and fit for rehabitation. This is the same criterion adopted in the case of leprous men and garments. (Leviticus 13:58.)