Leviticus 13:53-55

53“But if the priest sees that the mark has not spread in the garment, either in the warp or the woof, or on anything made of leather,

54then the priest shall order that they wash the thing in which the mark occurs, and he shall quarantine it for seven more days.

55The priest shall examine the article with the mark after it has been washed, and if the mark has not changed color, even though the mark has not spread, it is unclean; you shall burn it in the fire; it is a corroding mildew, whether on the top or on the front of it.