When the plague of leprosy is in a man,.... He has all the signs of it, and it is pretty manifest both to himself and others that it is upon him:

then he shall be brought unto the priest; by his friends and neighbours, if he is not willing to come of himself: a sinner insensible of the leprosy of sin, and of his unclean and miserable state through it, has no will to come to Christ the great High Priest for cleansing; but one that is sensible of it, and of Christ's ability to help and cleanse him, will come freely and gladly, and importunately seek to him for it; though indeed such an one is brought by powerful and efficacious grace to him, yet not against, but with his full will; see John 5:40; compare with this Matthew 8:1.

The second case (Leviticus 13:9-17): if the leprosy broke out without previous eruptions.

Leviticus 13:9-11

"If a mole of leprosy is in a man, and the priest to whom he is brought sees that there is a white rising in the skin, and this has turned the hair white, and there is raw (proud) flesh upon the elevation, it is an old leprosy." The apodosis to Leviticus 13:9 and Leviticus 13:10 commences with Leviticus 13:11. חי בּשׂר living, i.e., raw, proud flesh. מחיה the preservation of life (Genesis 45:5), sustenance (Judges 6:4); here, in Leviticus 13:10 and Leviticus 13:24, it signifies life in the sense of that which shows life, not a blow or spot (נגע, from מחה to strike), as it is only in a geographical sense that the verb has this signification, viz., to strike against, or reach as far as (Numbers 34:11). If the priest found that the evil was an old, long-standing leprosy, he was to pronounce the man unclean, and not first of all to shut him up, as there was no longer any doubt about the matter.

When the plague of leprosy is in a man, then he shall be brought unto the priest;

9-37. if the rising be white-This BRIGHT WHITE leprosy is the most malignant and inveterate of all the varieties the disease exhibits, and it was marked by the following distinctive signs: A glossy white and spreading scale, upon an elevated base, the elevation depressed in the middle, but without a change of color; the black hair on the patches participating in the whiteness, and the scaly patches themselves perpetually enlarging their boundary. Several of these characteristics, taken separately, belong to other blemishes of the skin as well; so that none of them was to be taken alone, and it was only when the whole of them concurred that the Jewish priest, in his capacity of physician, was to pronounce the disease a malignant leprosy. If it spread over the entire frame without producing any ulceration, it lost its contagious power by degrees; or, in other words, it ran through its course and exhausted itself. In that case, there being no longer any fear of further evil, either to the individual himself or to the community, the patient was declared clean by the priest, while the dry scales were yet upon him, and restored to society. If, on the contrary, the patches ulcerated and quick or fungous flesh sprang up in them, the purulent matter of which, if brought into contact with the skin of other persons, would be taken into the constitution by means of absorbent vessels, the priest was at once to pronounce it an inveterate leprosy. A temporary confinement was them declared to be totally unnecessary, and he was regarded as unclean for life [Dr. Good]. Other skin affections, which had a tendency to terminate in leprosy, though they were not decided symptoms when alone, were: "a boil" (Le 13:18-23); "a hot burning,"-that is, a fiery inflammation or carbuncle (Le 13:24-28); and "a dry scall" (Le 13:29-37), when the leprosy was distinguished by being deeper than the skin and the hair became thin and yellow.

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?