Leviticus 13:30

28 And if the bright spot stay in his place, spread not in the skin, but it somewhat dark; it a rising of the burning, and the priest shall pronounce him clean: for it an inflammation of the burning.

29 If a man or woman have a plague upon the head or the beard;

30 Then the priest shall see the plague: and, behold, if it in sight deeper than the skin; in it a yellow thin hair; then the priest shall pronounce him unclean: it a dry scall, a leprosy upon the head or beard.

31 And if the priest look on the plague of the scall, and, behold, it not in sight deeper than the skin, and no black hair in it; then the priest shall shut up the plague of the scall seven days:

32 And in the seventh day the priest shall look on the plague: and, behold, the scall spread not, and there be in it no yellow hair, and the scall not in sight deeper than the skin;