Leviticus 13:55-57

⁵⁵and the priest shall look on the plague, after that it is washed: and behold, if the plague have not changed his colour, and the plague be not spread; it is unclean; thou shalt burn it in the fire; it is fret inward, whether it be bare within or without.

⁵⁶And if the priest look, and behold, the plague be somewhat dark after the washing of it; then he shall rend it out of the garment, or out of the skin, or out of the warp, or out of the woof:

⁵⁷and 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.