Leviticus 13:27
And the priest shall look upon him the seventh day: and if it be spread much abroad in the skin, then the priest shall pronounce him unclean: it is the plague of leprosy. And the priest shall look upon him the seventh day: and if it be spread much abroad in the skin, then the priest shall pronounce him unclean: it is the plague of leprosy.
Leviticus 13:27 belongs to the laws in Leviticus 12-15 regulating uncleanness, leprosy, cleanliness, health, sanitation, and cleansing, which govern the examination of leprosy. On the seventh day the priest inspected the affected person, and if the mark had spread widely over the skin he pronounced the person unclean and identified the condition as the plague of leprosy. These laws also required proper precautions against disease.
Leprosy is a horrible disease shown here in its utmost loathsomeness, and as such it is a fitting type, picture, and prefigure of sin, including mortal sin. Like leprosy, sin is widespread, infectious, destructive, and incurable by human means and does not heal by itself, with its chief seat within. It pollutes and shames the person and pollutes the lives of others by spreading to them and influencing them to sin, and as a dreadful spiritual and moral disease it leaves people in need of healing.
Moses made leprosy a type of mortal sin, and Jesus made it a showing of his power to heal. Such visible physical uncleanness had to be removed before the sanctuary could undergo its cleansing with blood. The sanitary laws promulgated by Moses still stand at the head of sanitary law and give conclusive evidence of the divine inspiration guiding Moses. Leprosy remains as prevalent in the Holy Land as in scriptural days, so bearing witness to scriptural truth. These laws form part of a cleansing work that applies to believers, who are urged not to abandon health reform or other truths about cleansing.