Leviticus 13:31-33

31But if the priest examines the scabby disease and it does not look deeper than the rest of the skin and there is no black hair in it, the priest must put the person with the scabby disease in isolation for seven days.

32On the seventh day the priest will examine the disease. If the scab has not spread, there is no yellow hair on it, and the scab does not look deeper than the rest of the skin,

33the person will shave everything except the scab. The priest will put the person with the scab in isolation for another seven days.