Leviticus 13:2-5

2“If anyone has a sore, a rash, or an irritated area on his skin that turns into an infectious skin disease, he must be taken to the priest Aaron or to one of his sons who are also priests.

3The priest will examine the disease. If the hair in the diseased area has turned white, and the diseased area looks deeper than the rest of his skin, it is an infectious skin disease. When the priest has examined him, he must declare him unclean.

4But if the irritated area is white and does not look deeper than the rest of the skin, and the hair has not turned white, the priest must put him in isolation for seven days.

5On the seventh day the priest will examine him again. If the disease looks the same and has not spread, the priest must put him in isolation for another seven days.