Leviticus 13:1

“And the Lord spake unto Moses and unto Aaron, etc.] Aaron is addressed again, though left out in the preceding law, because the laws concerning leprosy chiefly concerned the priests, whose business it was to judge of it, and cleanse from it; and so Ben Gersom observes, mention is made of Aaron here, because to him and his sons belonged the affair of leprosies, to pronounce unclean or clean, to shut up or set free, and, as Aben Ezra says, according to his determination were all the plagues or strokes of a man, who should be declared clean or unclean: saying; as follows.”

“THE LAWS AND TOKENS IN DISCERNING LEPROSY. (Lev. 13:1-59) When a man shall have in the skin, &c.--The fact of the following rules for distinguishing the plague of leprosy being incorporated with the Hebrew code of laws, proves the existence of the odious disease among that people. But a short time, little more than a year (if so long a period had elapsed since the exodus) when symptoms of leprosy seem extensively to have appeared among them; and as they could not be very liable to such a cutaneous disorder amid their active journeyings and in the dry open air of Arabia, the seeds of the disorder must have been laid in Egypt, where it has always been endemic. There is every reason to believe…”

“13:1–14:57 Concerning the regulations pertaining to infections, the principle of normal and abnormal comes into play (see “Clean, Unclean, and Holy” Theme Note). Whether in a person, clothing, or a building, infections are not normal: They indicate disease and death, the antitheses of wholeness, and were therefore declared unclean. 13:1-46 a serious skin disease (Hebrew tsara‘at): The Hebrew word is much broader than the severely disfiguring Hansen’s disease (see study note on 13:2). This larger range included symptoms such as an open sore (13:10), a boil (13:18), a burn (13:24), a sore on the head or chin (13:29), shiny white patches (13:38), or abnormal baldness (13:40). A general test was…”

“Leprosy. - The law for leprosy, the observance of which is urged upon the people again in Deu 24:8-9, treats, in the first place, of leprosy in men: (a) in its dangerous forms when appearing either on the skin (vv. 2-28), or on the head and beard ( Lev 13:29-37); (b) in harmless forms ( Lev 13:38 and Lev 13:39); and (c) when appearing on a bald head ( Lev 13:40-44). To this there are added instructions for the removal of the leper from the society of other men ( Lev 13:45 and Lev 13:46). It treats, secondly, of leprosy in linen, woollen, and leather articles, and the way to treat them ( Lev 13:47-59); thirdly, of the purification of persons recovered from leprosy (Lev 14:1-32); and fourthly,…”