Leviticus 13:54-59

54 he shall order that the spoiled article be washed. Then he is to isolate it for another seven days.
55 After the article has been washed, the priest is to examine it again, and if the mold has not changed its appearance, even though it has not spread, it is unclean. Burn it, no matter which side of the fabric has been spoiled.
56 If, when the priest examines it, the mold has faded after the article has been washed, he is to tear the spoiled part out of the fabric, the leather, or the woven or knitted material.
57 But if it reappears in the fabric, in the woven or knitted material, or in the leather article, it is a spreading mold; whatever has the mold must be burned.
58 Any fabric, woven or knitted material, or any leather article that has been washed and is rid of the mold, must be washed again. Then it will be clean.”
59 These are the regulations concerning defiling molds in woolen or linen clothing, woven or knitted material, or any leather article, for pronouncing them clean or unclean.