Leviticus 13:31-33

31But if, when the priest examines the sore, it does not seem to be more than skin deep and there is no black hair in it, then the priest is to isolate the affected person for seven days.

32On the seventh day the priest is to examine the sore, and if it has not spread and there is no yellow hair in it and it does not appear to be more than skin deep,

33then the man or woman must shave themselves, except for the affected area, and the priest is to keep them isolated another seven days.