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, ver. 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.
40, 41. bald … forehead bald—The falling off of the hair, when the baldness commences in the back part of the head, is another symptom which creates a suspicion of leprosy. But it was not of itself a decisive sign unless taken in connection with other tokens, such as a "sore of a reddish white color" [Le 13:43]. The Hebrews as well as other Orientals were accustomed to distinguish between the forehead baldness, which might be natural, and that baldness which might be the consequence of disease.