Negaim, Chapter 11, Mishnah 2. This chapter is devoted to nigei begadim, the tzara'as that appears in a garment, and the Torah restricts this tumah to particular materials: wool, flax and leather. Our Mishnah asks what happens when a qualifying material is blended together with one that does not qualify, and the garment is woven from the mixture.
What "wool" means
The foundation of the Mishnah is that when the Torah says tzemer without further specification, it means tzemer recheilim, the wool of sheep, and nothing else. This same principle appears elsewhere in halachah: according to the shitah of Rabbeinu Tam in the laws of tzitzis, one fulfills the mitzvah on the level of de'oraisa only with a garment of linen or of sheep's wool. Other materials, however fine, do not carry a Torah obligation of tzitzis. Here too, sheep's wool is inside the parshah and other animal fibers are outside it.
Camel wool blended with sheep wool
The Mishnah therefore states: "tzemer gemalim vetzemer recheilim shetarafam zeh bazeh" - camel wool, which is not the wool the Torah speaks of, and sheep wool, which is, that a person combined with one another. He blended the fibers, spun the threads together, and produced from the mixture a single garment. What is its status?
- Where camel wool forms the majority of the blend, the Mishnah rules "einam mitamim benega'im": no tumah of nega'im can take hold in such a garment.
- Where the sheep wool is the larger portion, the ruling reverses, "mitamim benega'im", and the garment can indeed contract this tumah.
- "Mechtza lemechtza", when the two fibers stand in exactly equal proportion, the garment is likewise subject to nega'im.
That last ruling, that an even mixture is tamei, is how we pasken. The Kesef Mishneh points out that this is deliberately not in accordance with the shitah of Rabbi Shimon recorded in the Tosefta of Negaim, who reasoned that since a doubt in the laws of nega'im is resolved leniently, an equal mixture should be tahor. The Rosh does cite Rabbi Shimon's position, but the Tosfos Yom Tov notes that as a general matter the halachah here follows the ruling of the Mishnah as our Rabbanim transmitted it: half and half is tamei.
The Tiferes Yisroel: this is not a case of doubt
The Yachin u'Boaz of the Tiferes Yisroel makes a fine point about the reasoning behind the ruling. One might have imagined that an equal mixture is declared tamei because of some uncertainty, a worry that perhaps the sheep's wool slightly outweighs the camel's. He rejects that reading on two grounds.
First, we hold that where a measurement is produced by human hands rather than by Heaven, biydei adam efshar letzamtzem, an exact and precise quantity is attainable. A person mixing fibers can genuinely make them equal, and we can genuinely know that neither one predominates. Second, if this were merely a doubt, the lenient outcome would follow anyway, for the established rule is that a doubt in nega'im that arises before the matter has become bound up with tumah is resolved as tahor.
The correct explanation, therefore, is that we are not dealing with a doubt at all but with a positive requirement. To be exempt, the garment must be characterized by the material that lies outside the parshah; the camel wool has to be dominant enough for the garment to be defined as something other than sheep's wool. It is not that we need the garment to be defined as sheep's wool in order to be tamei; rather, we need it to be definable as non-sheep's wool in order to be free of nigei begadim. An even blend simply fails that test, and the garment remains within the law.
Flax and hemp
The Mishnah closes by applying the identical rule to the vegetable fibers: "vechen hapishtan vehakanbos shetarafam zeh bazeh". Pishtan, flax, is a material the Torah includes in nigei begadim; kanbos, hemp or canvas, is not. If the two were blended, spun together and woven into a single garment, then if the hemp predominates the garment is outside the laws of nigei begadim, and if the flax predominates it is subject to them. And where the two are present in equal measure, here too the garment is susceptible, mitamim benega'im, for exactly the reason we have seen: nothing has established it as a garment other than one of flax.