Leviticus 13:8

13:8 The priest must then examine it, and if the scab has spread on the skin, then the priest is to pronounce the person unclean. It is a disease.

Leviticus 13:23

13:23 But if the bright spot stays in its place and has not spread, it is the scar of the boil, so the priest is to pronounce him clean.

14:39 The priest must return on the seventh day and examine it, and if the infection has spread in the walls of the house,

14:44 the priest is to come and examine it, and if the infection has spread in the house, it is a malignant disease in the house. It is unclean.