12 And if the leprosy break out abroad in the skin, and the leprosy cover all the skin of [him that hath] the plague from his head even to his feet, as far as appeareth to the priest; 13 then the priest shall look; and, behold, if the leprosy have covered all his flesh, he shall pronounce [him] clean [that hath] the plague: it is all turned white: he is clean. 14 But whensoever raw flesh appeareth in him, he shall be unclean. 15 And the priest shall look on the raw flesh, and pronounce him unclean: the raw flesh is unclean: it is leprosy. 16 Or if the raw flesh turn again, and be changed unto white, then he shall come unto the priest; 17 and the priest shall look on him; and, behold, if the plague be turned into white, then the priest shall pronounce [him] clean [that hath] the plague: he is clean.
Matthew Henry's Commentary on Leviticus 13:12-17
Commentary on Leviticus 13:1-17
(Read Leviticus 13:1-17)
The plague of leprosy was an uncleanness, rather than a disease. Christ is said to cleanse lepers, not to cure them. Common as the leprosy was among the Hebrews, during and after their residence in Egypt, we have no reason to believe that it was known among them before. Their distressed state and employment in that land must have rendered them liable to disease. But it was a plague often inflicted immediately by the hand of God. Miriam's leprosy, and Gehazi's, and king Uzziah's, were punishments of particular sins; no marvel there was care taken to distinguish it from a common distemper. The judgment of it was referred to the priests. And it was a figure of the moral pollutions of men's minds by sin, which is the leprosy of the soul, defiling to the conscience, and from which Christ alone can cleanse. The priest could only convict the leper, (by the law is the knowledge of sin,) but Christ can cure the sinner, he can take away sin. It is a work of great importance, but of great difficulty, to judge of our spiritual state. We all have cause to suspect ourselves, being conscious of sores and spots; but whether clean or unclean is the question. As there were certain marks by which to know it was leprosy, so there are marks of such as are in the gall of bitterness. The priest must take time in making his judgment. This teaches all, both ministers and people, not to be hasty in censures, nor to judge anything before the time. If some men's sins go before unto judgment, the sins of others follow after, and so do men's good works. If the person suspected were found to be clean, yet he must wash his clothes, because there had been ground for the suspicion. We have need to be washed in the blood of Christ from our spots, though not leprosy spots; for who can say, I am pure from sin?