18 "When a person has a boil and it heals 19 and in place of the boil there is white swelling or a reddish-white shiny spot, the person must present himself to the priest 20 for an examination. If it looks like it has penetrated the skin and the hair in it has turned white, the priest will pronounce him unclean. It is a serious skin disease that has broken out in the boil. 21 But if the examination shows that there is no white hair in it and it is only skin deep and has faded, the priest will put him in quarantine for seven days. 22 If it then spreads over the skin, the priest will diagnose him as unclean. It is infectious. 23 But if the shiny spot has not changed and hasn't spread, it's only a scar from the boil. The priest will pronounce him clean.
Matthew Henry's Commentary on Leviticus 13:18-23
Commentary on Leviticus 13:18-44
(Read Leviticus 13:18-44)
The priest is told what judgment to make, if there were any appearance of a leprosy in old sores; and such is the danger of those who having escaped the pollutions of the world are again entangled therein. Or, in a burn by accident, verse 24. The burning of strife and contention often occasions the rising and breaking out of that corruption, which proves that men are unclean. Human life lies exposed to many grievances. With what troops of diseases are we beset on every side; and thy all entered by sin! If the constitution be healthy, and the body lively and easy, we are bound to glorify God with our bodies. Particular note was taken of the leprosy, if in the head. If the leprosy of sin has seized the head; if the judgment be corrupted, and wicked principles, which support wicked practices, are embraced, it is utter uncleanness, from which few are cleansed. Soundness in the faith keeps leprosy from the head.