Leviticus 13:53-55

And if the priest sees that the mark is not increased in the clothing or in any part of the material or in the leather, Then the priest will give orders for the thing on which the mark is, to be washed, and to be shut up for seven days more: And if, after the mark has been washed, the priest sees that the colour of it is not changed and it is not increased, it is to be burned in the fire: the disease is working in it, though the damage may be inside or outside.