Leviticus 13:57
And if it appear still in the garment, either in the warp, or in the woof, or in any thing of skin; it is a spreading plague: thou shalt burn that wherein the plague is with fire. And if it appear still in the garment, either in the warp, or in the woof, or in any thing of skin; it is a spreading plague: thou shalt burn that wherein the plague is with fire.
Leviticus 13:57 belongs to the laws of cleansing given to ancient Israel that regulated uncleanness and leprosy, in which leprosy is a fitting type of sin. The law deals with plague in cloth and skin articles, where warp means the lengthwise threads, woof means the crosswise threads, and weft means the woven cloth itself. Garments made from such cloth are used in Scripture as figures of character.
If the mark still appears in the material, whether in warp or woof or anything of skin, it is a spreading plague and that wherein the plague is must be burned with fire. This was a physical and sanitary removal of uncleanness, part of sanitary instruction concerning leprosy and other contagious diseases intended to keep infectious contagion and germs from remaining in buildings and materials. That visible, physical removal of uncleanness had to take place before the sanctuary could undergo its cleansing with blood, and it was distinct from the sanctuary's real cleansing.
Leprosy in this law is a fitting type and figure of sin as a dreadful moral disease. Sin is universal, infectious, incurable by human means and destructive, having its chief seat within while also bringing outward pollution and shame, not healing by itself but spreading its pollution to others. Help comes from the great Physician, whose blood cleanses those who repent and believe. As shown with Naaman, people cannot keep pride and the old self and merely wish sin removed, for entry into God's kingdom requires pride to be put away and the old self to die and be replaced with the new, and without that humble spirit a person still needs conversion.
Israel's failure to remain faithful under those cleansing laws warns the remnant not to abandon health reform and other cleansing truths. The spreading plague persisting in dress teaches that pride and vanity in dress can spread harmful influence. Christians should therefore reject worldly fashions and dress in a way that distinguishes them from the world rather than misrepresenting Christ or leading weaker believers toward pride and vanity.