Leviticus 13:51, 52

On the seventh day he is to examine it, and if the mold has spread in the fabric, the woven or knitted material, or the leather, whatever its use, it is a persistent defiling mold; the article is unclean.

He must burn the fabric, the woven or knitted material of wool or linen, or any leather article that has been spoiled; because the defiling mold is persistent, the article must be burned.