Leviticus 13:57-59

If it appears still in the garment, either in the warp or in the woof, or in anything made of skin, it is spreading; you shall burn the diseased part with fire. But the garment, or the woven or knitted stuff or warp or woof, or anything made of skin from which the disease departs when you have washed it, shall then be washed a second time, and be clean. This is the law for a leprous disease in a garment of wool or linen, either in the warp or woof, or in anything made of skin, to pronounce it clean or unclean.