Leviticus 13:33

29 If a man or woman has an infection on the head or chin,

30 the priest shall examine the infection, and if it appears to be deeper than the skin and the hair in it is yellow and thin, the priest must pronounce him unclean; it is a scaly outbreak, an infectious disease of the head or chin.

31 But if the priest examines the scaly infection and it does not appear to be deeper than the skin, and there is no black hair in it, the priest shall isolate the infected person for seven days.

32 On the seventh day the priest is to reexamine the infection, and if the scaly outbreak has not spread and there is no yellow hair in it, and it does not appear to be deeper than the skin,

33 then the person must shave himself except for the scaly area. Then the priest shall isolate him for another seven days.

34 On the seventh day the priest shall examine the scaly outbreak, and if it has not spread on the skin and does not appear to be deeper than the skin, the priest is to pronounce him clean. He must wash his clothes, and he will be clean.

35 If, however, the scaly outbreak spreads further on the skin after his cleansing,

36 the priest is to examine him, and if the scaly outbreak has spread on the skin, the priest need not look for yellow hair; the person is unclean.

37 If, however, in his sight the scaly outbreak is unchanged and black hair has grown in it, then it has healed. He is clean, and the priest is to pronounce him clean.

Read all of Leviticus 13