Leviticus 13:53-59

“If the priest sees that the mildew has not spread in the cloth (either knitted or woven) or leather, he must order the people to wash that piece of leather or cloth. Then he must separate the clothing for seven more days. After the piece with the mildew has been washed, the priest must look at it again. If the mildew still looks the same, the piece is unclean, even if the mildew has not spread. You must burn it in fire; it does not matter if the mildew is on one side or the other. “But when the priest looks at that piece of leather or cloth, the mildew might have faded after the piece has been washed. Then the priest must tear the mildew out of the piece of leather or cloth (either woven or knitted). But if the mildew comes back to that piece of leather or cloth (either woven or knitted), the mildew is spreading. And whatever has the mildew must be burned with fire. When the cloth (either woven or knitted) or the leather is washed and the mildew is gone, it must be washed again; then it will be clean. “These are the teachings about mildew on pieces of cloth (either woven or knitted) or leather, to decide if they are clean or unclean.”