Leviticus 13:2

2.When a man shall have in the skin. Since every eruption was not the leprosy, and did not render a man unclean, when God appoints the priests to be the judges, He distinguishes by certain marks a common eruption from the leprosy; and then subjoins the difference between the various kinds of leprosy. For the disease was not always incurable; but, only when the blood was altogether corrupted, so that the skin itself had become hardened by its corrosion, or swollen by its diseased state. This, then, must be observed in the first place, that the Greek and Latin word lepra, and the Hebrew צרעת tzaragmath, extend further than to the incurable disease, which medical men call elephantiasis (4) both on account of the hardness of the skin, and also its mottled color; not, however, that there is an entire agreement between the thickness of the man’s skin and that of an elephant, but because this disease produces insensibility of the skin. This the Greeks call Ψώρα, and if it be not a kind of leprosy, it is nearly allied to it. Thus we see that there was a distinction between the scab and leprosy; just as now-a-days, if it were necessary to judge respecting the itch, (which is commonly called the disease of St. Menanus, (5) the marks must be observed, which distinguish it from leprosy. But, as to the various kinds of leprosy, I confess that I am not a physician, so as to discuss them accurately, and I purposely abstain from close inquiry about them, because I am persuaded that the disease here treated of affected the Israelites in an extraordinary manner, which we are now unacquainted with; for what do we now know of a leprous house? Indeed it is probable that, since heathen writers knew that the Jewish people suffered from this disease, they laid hold of it as the ground of their falsehood, that all the descendants of Abraham were infected with the itch, and were driven away from Egypt, lest others should catch it from them. That (6) this was an ancient calumny appears from Josephus, both in the ninth book of his Antiquities, and in his Treatise against Apion; and it is repeated both by C. Tacitus and Justin. Yet I make no doubt that the Egyptians, a very proud nation, in order to efface the memory of their own disgrace, and of the vengeance inflicted upon them by God, invented this lie, and thus grossly turned against this innocent people what had happened to themselves, when they were smitten with boils and blains. But we shall see hereafter, amongst God’s curses, that He chastised His people with the same plagues as He had inflicted on the Egyptians:

"The Lord will smite thee with the botch of Egypt, and with the emerods, and with the scab,” etc. (Deuteronomy 28:27.)

Whence it may be probably inferred, that God avenged the crimes of His ancient people with special judgments, which are now unknown to us; just as afterwards new diseases arose, from which those in old times were free. At any rate, Josephus, by clear and solid arguments, exposes the absurdity of this accusation, that Moses was driven from Egypt with a crowd of exiles, lest they should infect the country with their disease; because, if they had been universally affected with this malady, he never would have imposed such severe laws for separating the lepers from general society.

God first commands that, whenever a suspicion of leprosy arose, the man was to present himself to the priest; if any symptom of leprosy appeared, He commands him to be shut up for a period of seven days, until it should appear from the progress of the disease that it was incurable leprosy. That God should have appointed the priests to be judges, and those, too, only of the highest order, is a proof that His spiritual service was rather regarded than mere bodily health. If any shall inquire whether leprosy is not a contagious disease, and whether it be not therefore expedient that all who were affected by it should be removed from intercourse with others, I admit, indeed, that such is the case, but I deny that this was the main object in view. For, in process of time, physicians would have been better able to decide by their art and skill: whereas God enjoined this decision upon the priests alone, and gave them the rule whereby they were to judge. Nor did He appoint the Levites indiscriminately, but only the sons of Aaron, who were the highest order, in order that the authority of the decision might be greater. It was, then, by a gross error, or rather impudence, that the Papal priests (sacrifici) assumed to themselves this jurisdiction. It was (they say) the office of the chief priests under the Law to distinguish between the kinds of leprosy; and, therefore, the same right is transferred to the bishops. But they carry the mockery still further: the official (7) the bishop’s representative, sits as the legitimate judge; he calls in physicians and surgeons, from whose answers he pronounces what he confesses he is ignorant of himself. Behold how cleverly they accommodate a legal rite to our times! The mockery, however, is still more disgusting, when in another sense they extend to the whole tribe of priests what they have said to belong solely to the bishops; for, since the sin under which all labor is a spiritual leprosy, they thence infer that all are excluded from the congregation of the faithful until they shall have been purged and received by absolution, which they hold to be the common office of all the priests. They afterwards add, that judgment cannot be pronounced till the cause is heard, and so conclude that confession is necessary. But, if they choose to have recourse to subtleties, reason would rather conduct us to the opposite conclusion; for God did not desire the priests to take cognizance of a hidden disease, but only after the manifest symptoms had appeared: hence it will follow, that it is preposterous to bring secret sins to judgment, and that wretched men are dragged to their confession contrary to all law and justice. But, setting aside all these absurdities, an analogy must be observed between us and God’s ancient people. He of old forbade the external uncleanness of the flesh to be tolerated in His people. By Christ’s coming, the typical. figure has ceased; but we are taught that all uncleanness, whereby the purity of His services is defiled, is not to be cherished, or borne with amongst us. And surely excommunication answers to this ceremony; since by it the Church is purified, lest corruptions should everywhere assail it, if wicked and guilty persons occupied a place in it promiscuously with the good. The command of God that, whilst the disease was obscure and questionable, the infected person should be shut up for seven days, recommends moderation to us, lest any, who is still curable, should be condemned before his time. In fact, this medium is to be observed, that the judge should not be too remiss and hasty in pardoning, and still that he should temper severity by justice; and especially that he should not be too precipitate in his judgment. What we translate “shall pronounce him clean, or unclean,” is in Hebrew, “shall clean, or unclean him;” thus the dignity of the judgment is more fully established, as though it had proceeded from God Himself; and assuredly no medical skill could declare on the seventh day a leprosy to be incurable, respecting which there was doubt so short a time before, unless God should in some special manner discover the uncleanness, and guide the eyes of the priests by His Spirit.