Bechoros, Chapter 4, Mishnah 7. The next four Mishnahs deal with the laws applying to people who are suspected of transgressing the Torah. "Suspected" in this context is not a mere suspicion, but rather a person with a proven record: he committed the forbidden act, there are witnesses to it, and it was verified that he did so - and now the concern is lest he repeat it and do it again. How do we deal with this?
One suspected regarding firstborns:
The Mishnah before us discusses a person "hechashud al habechoros" - who is suspected regarding firstborns, meaning one who intentionally inflicted a blemish on a firstborn animal so that he can slaughter it and eat it or sell it. We are not concerned that he will slaughter the firstborn without any blemish at all, because the firstborn is consecrated, and slaughtering consecrated animals outside - slaughtering sacrificial animals outside the Temple - is a severe transgression punishable by kareis. However, there is a concern that he will inflict a blemish on the animal, such as in its eye, and subsequently slaughter it, eat it, or sell it.
The foundation of the law is as follows: A kohen who inflicts a blemish on a firstborn, besides violating a Torah prohibition, the Sages decreed that he is forbidden to benefit from the animal at all - he may not eat it, sell it, or use its hide or wool.
Since this person has already stumbled in this in the past, the Sages penalized him even more severely: "ein lokchin mimenu besar tzva'im" - we do not buy from him even meat coming from a deer. A deer is a wild animal and the law of firstborns does not apply to it at all, since the law of firstborns applies only to cows, goats, and sheep, and a deer is not brought as a sacrifice. Nevertheless, since deer meat is similar to calf meat, we are concerned lest he is selling calf meat that was slaughtered after he inflicted a blemish on it; and since he knows that people will not buy meat from him as calf, since he is suspected regarding firstborns, he will claim: "This is not calf meat but deer meat". Even such a sale was forbidden.
"Velo oros she'einam avudim" - And not untanned hides:
Similarly, we do not buy untanned hides from him. A kohen whose firstborn animal sustained a blemish in a permissible manner may slaughter it and use its hide for his needs; however, if he intentionally inflicted a blemish on it, the Sages penalized him that he may not eat the animal, and certainly he may not benefit from its hide. Therefore, if one suspected of selling firstborns is selling an animal hide, we do not buy from him, lest the hide comes from a firstborn on which he intentionally inflicted a blemish.
The Mishnah specifically stated "untanned hides", and the reason for this is rooted in a logic that is repeated in the following Mishnahs as well: the cost of the raw material is a relatively small part of the total cost of the finished product. It is unreasonable that a person would take a risk and save a small amount by obtaining forbidden raw materials, when faced with the possibility that if it becomes known where he obtained his hides, he will lose not only the hide itself, but also all the great effort he invested in tanning it and turning it into a finished product.
Therefore, with a raw hide, he has nothing to lose: the hide was obtained unlawfully to begin with, and if he succeeds in selling it, he will profit, and if not, his loss is small. Because of this, we are concerned that he will try to act deceitfully, and we do not buy raw hides from him. However, we are not concerned that he will sell tanned hides, since the risk is greater than the expected profit.
Dispute between Rabbi Eliezer and the Sages:
Rabbi Eliezer: "Lokchin heimenno oros shel nekeivah" - we may buy hides of female animals from him. The prohibition was only stated regarding the hide of a male animal, because the firstborn is always a male cow, goat, or sheep, whereas a female is certainly not a firstborn and there is nothing to fear. Furthermore, one can distinguish in the hide whether it comes from a male or a female.
The Sages: They disagree and say that he is able to cut the male's hide in a way that makes it look like a female's hide; and even if one can somehow distinguish the difference, he can claim: "Mice gnawed at the hide and therefore it looks strange, and I was forced to cut it this way".
The halachah is ruled in accordance with the opinion of the Tanna Kamma: we do not buy hides from the suspect, whether of males or of females.
"V'ein lokchin mimenu tzemer meluban vetzo'i" - and we do not buy from him whitened and dirty wool:
The wool itself is a raw material, and it is obvious that we do not buy it from him. The question arises regarding wool that has undergone whitening, since whitening involves work: is its status like raw hide or like processed hide? The answer is that its status is like raw hide, and we do not buy whitened wool from him, because cleaning the wool does not involve a great deal of work, and therefore he would take the risk.
The Mishnah's wording "whitened and dirty" literally means that we do not buy wool from him, whether it is whitened or dirty. However, the Gemara challenges that this is impossible: once you have said that we do not buy the wool when it is whitened, all the more so that we do not buy it when it is dirty and unprocessed. Therefore, this is not the meaning of the words, but rather it should be read as "whitened from its dirt" - wool that has been cleaned of its dirt.
"Aval lokchin meihen tavi uvegadim" - but we may buy from them spun wool and garments:
What is permitted to buy from the wool products is wool that has been spun into threads or made into garments, since this involves a great deal of work, and a person would not risk all his labor when he is liable to lose everything - exactly the same reason stated regarding the processing of hides.
There is an inference to be made here: once the Mishnah permitted "spun wool", meaning spun threads which involve a certain amount of work, it is obvious that woven garments, which involve much more work, are permitted. Why, then, did the Mishnah list both of them?
The Gemara answers that it is referring to garments whose threads were not even spun, but rather were made like felt garments: there is no spinning here at all, but rather the compression of fibers together, as we learned in Tractate Keilim. Both of these are permitted, because a person would not risk all that work lest it be taken from him. Therefore, it is permitted to buy spun wool or felt garments from someone suspected of selling firstborn animals unlawfully, and all the more so regular garments.
In summary: In this Mishnah we learned the laws of one suspected regarding firstborns - someone who has been proven to have intentionally inflicted a blemish on a firstborn animal. The Sages penalized him that we do not buy deer meat from him (lest it be calf meat), and we do not buy unprocessed hides or wool that has been cleaned of its dirt from him. The emerging principle is: whenever the work invested in it is minimal, we suspect that he will take the risk and sell it; but whenever a great deal of work has been invested in it - spun wool, felt garments, and woven garments - we do not suspect him, and it is permitted to buy from him. Rabbi Eliezer and the Sages disagreed regarding female hides, and the halachah follows the Tanna Kamma to forbid all hides.
In the following Mishnayos, we will continue to discuss other suspected individuals and the laws that apply to them.