We have here,
I. Provisos that neither a freckled skin nor a bald head should be mistaken for a leprosy, Lev 13:38-41. Every deformity must not forthwith be made a ceremonial defilement. Elisha was jeered for his bald head (Kg2 2:23); but it was the children of Bethel, that knew not the judgments of their God, who turned it to his reproach.
II. A particular brand set upon the leprosy if at any time it did appear in a bald head: The plague is in his head, he is utterly unclean, Lev 13:44. If the leprosy of sin have seized the head, if the judgment be corrupted, and wicked principles which countenance and support wicked practices, be embraced, it is an utter uncleanness, from which few are ever cleansed. Soundness in the faith keeps the leprosy from the head, and saves conscience from being shipwrecked.
III. Directions what must be done with the convicted leper. When the priest, upon mature deliberation, had solemnly pronounced him unclean,
1. He must pronounce himself so, Lev 13:45. He must put himself into the posture of a mourner and cry, Unclean, unclean. The leprosy was not itself a sin, but it was a sad token of God's displeasure and a sore affliction to him that was under it. It was a reproach to his name, put a full stop to his business in the world, cut him off from conversation with his friends and relations, condemned him to banishment till he was cleansed, shut him out from the sanctuary, and was, in effect, the ruin of all the comfort he could have in this world. Heman, it would seem, either was a leper or alludes to the melancholy condition of a leper, Psa 88:8, etc. He must therefore, (1.) Humble himself under the mighty hand of God, not insisting upon his cleanness when the priest had pronounced him unclean, but justifying God and accepting the punishment of his iniquity. He must signify this by rending his clothes, uncovering his head, and covering his upper lip, all tokens of shame and confusion of face, and very significant of that self-loathing and self-abasement which should fill the hearts of penitents, the language of which is self-judging. Thus must we take to ourselves the shame that belongs to us, and with broken hearts call ourselves by our own name, Unclean, unclean - heart unclean, life unclean, unclean by original corruption, unclean by actual transgression - unclean, and therefore worthy to be for ever excluded from communion with God, and all hope of happiness in him. We are all as an unclean thing (Isa 64:6) - unclean, and therefore undone, if infinite mercy do not interpose. (2.) He must give warning to others to take heed of coming near him. Wherever he went, he must cry to those he saw at a distance, "I am unclean, unclean, take heed of touching me." Not that the leprosy was catching, but by the touch of a leper ceremonial uncleanness was contracted. Every one therefore was concerned to avoid it; and the leper himself must give notice of the danger. And this was all that the law could do, in that it was weak through the flesh; it taught the leper to cry, Unclean, unclean, but the gospel has put another cry into the lepers' mouths, Luk 17:12, Luk 17:13, where we find ten lepers crying with a loud voice, Jesus, Master, have mercy on us. The law only shows us our disease; the gospel shows us our help in Christ.
2. He must then be shut out of the camp, and afterwards, when they came to Canaan, out of the city, town, or village, where he lived, and dwell alone (Lev 13:46), associating with none but those that were lepers like himself. When king Uzziah became a leper, he was banished from his palace, and dwelt in a separate house, Ch2 26:21. And see Kg2 7:3. This typified the purity which ought to be preserved in the gospel church, by the solemn and authoritative exclusion of scandalous sinners, that hate to be reformed, from the communion of the faithful. Put away from among yourselves that wicked person, Co1 5:13.

The scall shall he not shave - Lest the place should be irritated and inflamed, and assume in consequence other appearances besides those of a leprous infection; in which case the priest might not be able to form an accurate judgment.

And he that hath his hair fallen off from the part of his head towards his face,.... That is, from the crown of his head towards his forehead and temples, the fore part of his head; and so the Misnic doctors distinguish baldness, which is from the crown of the head descending behind to the channel of the neck; and that here mentioned, which is from the crown of the head descending to his face and forehead, over against the hair above (x):

he is forehead bald; to distinguish him from him that is bald behind:

yet is he clean; as the other: these cases are observed, that it might not be concluded that every man that shed his hair or was bald either before or behind was a leper, because the hair of a leper used to fall off from him; if he had not the other signs of leprosy, and which were the sure and true signs of it before mentioned.

(x) Misn. Negaim, c. 10. sect. 10.

If a man . . . or a woman have in the skin of their flesh bright spots--This modification of the leprosy is distinguished by a dull white color, and it is entirely a cutaneous disorder, never injuring the constitution. It is described as not penetrating below the skin of the flesh and as not rendering necessary an exclusion from society. It is evident, then, that this common form of leprosy is not contagious; otherwise Moses would have prescribed as strict a quarantine in this as in the other cases. And hereby we see the great superiority of the Mosaic law (which so accurately distinguished the characteristics of the leprosy and preserved to society the services of those who were laboring under the uncontagious forms of the disease) over the customs and regulations of Eastern countries in the present day, where all lepers are indiscriminately proscribed and are avoided as unfit for free intercourse with their fellow men.