NEGA'IM ("Plagues," "Leprosy"):
A treatise of the order Ṭohorot in the Mishnah and the Tosefta, which treats of the rules concerning leprosy and the infection of clothing and dwellings (Lev. xiii., xiv.). In most editions it is the fourth treatise of the order, and it is divided into fourteen chapters containing one hundred and fifteen paragraphs in all.
- Ch. i.: Different kinds of leprosy (§§ 1-4); days on which leprosy may first be inspected; deferment of the subsequent inspection to the following day if the day set falls on a Sabbath; the aggravating or ameliorating consequences attending such a postponement (§§ 4-6).
- Ch. ii.: Time of day at which leprosy may be inspected; the priests who make the inspection; the priest may not inspect leprosy on his own body, garment, or house. In this connection it is statedthat a wise man may not redeem his own vows nor inspect his own firstlings.
- Ch. iii.: Those who are defiled by leprosy; time after which, and signs by which, the different kinds of leprosy are declared to be unclean.
- Ch. iv.: The different signs which indicate that leprosy is unclean; ways in which the different signs cause defilement; concerning the simultaneous appearance of two signs in a case of leprosy.
- Ch. v.: Doubtful cases of leprosy; doubtful cases of leprosy in which it is considered as unclean or as clean.
- Ch. vi.: Size of the leprous spot, and how it becomes unclean by the sound flesh in it; the twenty-four extremities of limbs, which do not cause uncleanness, although they are sound flesh in a leprous spot; parts of the human body which do not become unclean through a leprous spot.
- Ch. vii.: Leprous spots in general which are clean; changes in the spot; cases in which the spot becomes clean by removing the sign of uncleanness; cases in which the leprosy is entirely cut away.
- Ch. viii.: The spreading of leprosy over the entire body; cases in which such a spread causes uncleanness, and those in which it causes cleanness; how the reappearance of the extremities of limbs nullifies the effect of the spreading; advantages and disadvantages arising from showing one's leprosy to the priest.
- Ch. ix.: Time after which, and signs by which, boils ("sheḥin") and burnings ("miḳwah") are declared unclean.
- Ch. x.: Time after which, and signs by which, scall on the head or in the beard ("neteḳ") is declared unclean; similar regulations concerning baldness and its cause.
- Ch. xi.: Garments which may become unclean through leprosy; neither garments of pagans nor garments made of the skins of marine animals or of camel's hair become unclean through leprosy; time after which, and signs by which, leprosy on garments is declared unclean; contact of a leprous garment with other garments.
- Ch. xii.: Houses which may become unclean through leprosy, and the symptoms of the form of leprosy which causes this uncleanness; inspection of a house in which leprosy appears; origin of the proverb: "Wo to the wicked and wo to his neighbors!"
- Ch. xiii.: Further details regarding a house defiled by leprosy; how a clean person becomes unclean by entering a defiled house, and how an unclean person defiles a house by entering it.
- Ch. xiv.: Purification of a leper; concerning the pair of birds which are requisite, the shaving of the hair, and the offering which must be brought.
The Tosefta to this treatise, which has only nine chapters, contains details not found in the Mishnah, and includes other interesting passages, of which the following is the most noteworthy (vi. 1): "There never has been a house infected with leprosy [in the manner described in Lev. xiv. 34 et seq.], and there never will be one; the regulations regarding such a house have only a theoretical bearing."