Leviticus 13:4-6

4If the mark on the skin is white but not under the skin it might not be a disease. If the hair on the skin is not white, it might not be a bad disease. The priest must keep him separate from the people for seven days.

5On the seventh day, the priest must look at the person. The mark may not be any bigger. If it is not, he must keep the person separate from the people for seven more days.

6On the seventh day, the priest must look at the person. The mark may not be so dark and it may not be any bigger. The priest can say that the disease has left that person. The person must wash his clothes.