31 But 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.

Read Leviticus 13:31 Using Other Translations

And if the priest look on the plague of the scall, and, behold, it be not in sight deeper than the skin, and that there is no black hair in it; then the priest shall shut up him that hath the plague of the scall seven days:
And if the priest examines the itching disease and it appears no deeper than the skin and there is no black hair in it, then the priest shall shut up the person with the itching disease for seven days,
If the priest examines the scabby sore and finds that it is only skin-deep but there is no black hair on it, he must quarantine the person for seven days.