Leviticus 13:7-8

ISV(i) 7 But if the scab did spread in the skin after he presented himself to the priest for cleansing, then he is to show himself a second time to the priest. 8 When the priest examines him and determines that the scab did, in fact, spread in his skin, then the priest is to pronounce him unclean, since it’s an infectious skin disease.”