Leviticus 13:1-3

GOD spoke to Moses and Aaron: “When someone has a swelling or a blister or a shiny spot on the skin that might signal a serious skin disease on the body, bring him to Aaron the priest or to one of his priest sons. The priest will examine the sore on the skin. If the hair in the sore has turned white and the sore appears more than skin deep, it is a serious skin disease and infectious. After the priest has examined it, he will pronounce the person unclean.