Leviticus 13:57-59

57But if it reappears in the fabric, the warp or weft, or any leather article, it has broken out again. You must burn whatever is contaminated.

58But if the contamination disappears from the fabric, the warp or weft, or any leather article, which have been washed, it is to be washed again, and it will be clean.

59“This is the law concerning a mildew contamination in wool or linen fabric, warp or weft, or any leather article, in order to pronounce it clean or unclean.”