Leviticus 13:1-8

Leprosy, a name applied to several different diseases, was greatly feared in Bible times. Some of these diseases, unlike the disease we call leprosy or Hansen’s disease today, were highly contagious. The worst of them slowly ruined the body, and in most cases, were fatal. Lepers were separated from family and friends, and confined outside the camp. Since priests were responsible for the health of the camp, it was their duty to expel and readmit lepers. If someone’s leprosy appeared to go away, only the priest could decide if he was truly cured. Leprosy is often used in Bible times as an illustration of sin, because sin is contagious and destructive, and leads to separation.

(Life Application Study Bible pg. 198)