Leviticus 13
3 Ref and the priest shall examine the plague in the skin of the body: and if the hair in the plague has turned white, and the appearance of the plague is deeper than the body's skin, it is the plague of leprosy; and the priest shall examine him, and pronounce him unclean.
4 Ref If the bright spot is white in the skin of his body, and the appearance of it isn't deeper than the skin, and the hair of it hasn't turned white, then the priest shall isolate the infected person for seven days.