Today's discussion begins with the principle that anything the Torah deems an abomination is forbidden not only for consumption but also for any benefit, unless the Torah explicitly states otherwise. The classic example is a nevelah, an animal that died without proper ritual slaughter. While the general rule for forbidden foods is "do not eat and do not benefit," the verse concerning nevelah states, "you may give it to the convert (ger) or sell it to a foreigner (goy)." This explicit allowance indicates that for nevelah, benefit is permitted. The convert mentioned here is a ger toshav, a non-Jew residing in the Land of Israel who has accepted the seven Noahide laws, not a full convert, as a full convert would be forbidden to eat nevelah just like any other Jew.
The Gemara then analyzes the phrasing regarding nevelah. The verse says, "you may give it to the convert or sell it to a foreigner." The term "or" (או) implies a choice: either give it as a gift to the ger toshav or sell it to the goy. Rebbe Yehuda, however, holds that one can even sell it to a ger toshav. This interpretation requires understanding "or" differently, or perhaps reading the verse as allowing both gifting to a ger toshav and selling to a goy, and then extending the sale option to the ger toshav. Rebbe Meir, on the other hand, interprets the "or" as indicating a priority: first offer it as a gift to the ger toshav, and if that is not feasible, then sell it to the goy. He argues that there's no need for a verse to permit gifting to a ger toshav, as we are obligated to support a ger toshav, and therefore, gifting him a nevelah is a natural act of support, not a special allowance requiring a verse.
The Gemara then explores the general rule that "anything forbidden for consumption is also forbidden for benefit unless the Torah explicitly permits it." It challenges this rule with several examples. First, regarding "something created on Shabbat" (מעשה שבת), if a Jew cooked on Shabbat, the food is forbidden for that Jew, but it is not forbidden for benefit for everyone else forever. Rather, it is only forbidden for a specific duration as a rabbinic penalty (knas), not a Torah prohibition. The Gemara answers that Shabbat is holy (קדוש), but the act performed on Shabbat (מעשה שבת) does not become holy itself, and therefore, the product remains permissible for benefit.
Next, the Gemara considers the prohibition of plowing with an ox and a donkey together (חורש בשור ובחמור) or muzzling an animal while it plows (לא תחסום שור בדישו). If someone violates these prohibitions, the produce of the field is not forbidden for benefit. This seems to contradict the general rule that a forbidden act renders the resulting product forbidden for benefit. Rashi explains that these cases involve a forbidden action, but the resulting produce is not inherently the forbidden item itself. Eating the produce is not eating the ox or the donkey, nor is it eating the muzzle. In contrast, when the Torah says "do not eat," it refers to the actual forbidden item, not a byproduct.
The Gemara then discusses kilayim, the mixing of species. Specifically, kil'ei zera'im (mixed seeds) and kil'ei hakerem (mixed seeds in a vineyard). While kil'ei zera'im are forbidden to plant, their produce is permissible for benefit. However, kil'ei hakerem are forbidden for benefit, and the verse uses the term "lest it become holy" (פן תקדש), implying it must be burned. The Gemara notes that the Torah explicitly states the prohibition of benefit for kil'ei hakerem, implying that for other kilayim, benefit is permitted. A connection (היקש) is drawn between mixing animals (בהמה) and mixing seeds in a field (שדה), stating that just as the offspring of mixed kosher animals are permissible to eat, so too the produce of mixed seeds in a field is permissible for benefit.
The Gemara then brings the prohibition of "an animal and its offspring on the same day" (אותו ואת בנו). If one slaughters a mother animal and its offspring on the same day, it is forbidden. However, the meat itself is not forbidden for benefit. This is another example where a forbidden act does not render the resulting product forbidden for benefit. Similarly, with the mitzvah of "sending away the mother bird" (שילוח הקן), if one takes the mother bird before sending her away, the bird does not become forbidden for benefit. The Torah would not command an act that could lead others to stumble by finding and eating a forbidden bird without knowing its status.
The Gemara then seeks the source for the prohibition of basar b'chalav (meat and milk). It considers the verse regarding the Korban Pesach (Paschal offering), which states "do not eat it raw or cooked" (לא תאכלו ממנו נא ובשל). The additional word for "cooked" (בשל) is seen as superfluous, implying an additional type of cooking that is forbidden. This is then applied to basar b'chalav, suggesting that just as cooking the Korban Pesach improperly is forbidden, so too cooking meat in milk is forbidden.
Rebbi Yochanan offers a different source. He derives it from the prohibition of pisulei mukdashim (blemished consecrated animals). The verse states "do not eat it" (לא תאכלנו) regarding the blood of pisulei mukdashim. Since the blood is already known to be forbidden, this extra prohibition must refer to something else. Through a principle of "a matter learned from its context" (דבר הלמד מעניינו), since pisulei mukdashim are a mixture of sacred (קדש) and non-sacred (חולין) elements (as they were consecrated but then redeemed due to a blemish), the verse is understood to refer to another "mixture of two species" (שני מינים), which is basar b'chalav. However, this derivation only prohibits consumption, not benefit, as benefit is permitted from pisulei mukdashim (e.g., their shearing or labor). Thus, another verse is needed to prohibit benefit from basar b'chalav, similar to the Korban Pesach which prohibits both consumption and benefit.
The Gemara then brings a proof from the verse "for you are a holy people" (כי עם קדוש אתה), which appears in the context of basar b'chalav. This is juxtaposed with the prohibition of a male prostitute (קדש), which also uses the term "holy" (קדוש) and is forbidden for benefit. This suggests that basar b'chalav, being associated with holiness, is also forbidden for benefit.
Another proof for basar b'chalav being forbidden for benefit comes from its proximity to the laws of nevelah. The Torah states, "do not eat any nevelah," followed immediately by "do not boil a kid in its mother's milk" (לא תבשל גדי בחלב אמו). Since the Torah permits selling nevelah to a goy, the juxtaposition implies that one should not cook the nevelah in milk before selling it. This indicates that cooking basar b'chalav is forbidden, and by extension, benefit is forbidden.
The Torah repeats the phrase "do not boil a kid in its mother's milk" three times. The Gemara learns three distinct prohibitions from these repetitions: one for consumption (איסור אכילה), one for benefit (איסור הנאה), and one for the act of cooking itself (איסור בישול).
The Gemara then explores the source for the prohibition of benefit from basar b'chalav. It suggests a kal vachomer (a fortiori argument) from orlah (fruit of a tree in its first three years). Just as orlah is forbidden for benefit even though no forbidden act was performed (the fruit grew naturally), then basar b'chalav, where a forbidden act (cooking) was performed, should certainly be forbidden for benefit. However, this is challenged because orlah is forbidden from its very inception (sheken lo hayta la sha'at heter), whereas basar b'chalav (meat and milk separately) were permissible before being combined. The Gemara counters with chametz b'Pesach (leavened bread on Passover), which was permissible before Passover but becomes forbidden for benefit on Passover. This shows that something can become forbidden for benefit even if it had a period of permissibility.
The discussion then turns to kil'ei hakerem, which is also forbidden for benefit despite not carrying the severe penalty of karet. The Gemara concludes that the prohibition of benefit for basar b'chalav is derived from these three cases: orlah, chametz b'Pesach, and kil'ei hakerem. These three are all forbidden for benefit, and their commonality is that they are forbidden. Therefore, basar b'chalav, which is also forbidden, should likewise be forbidden for benefit.
A challenge arises: orlah, chametz, and kil'ei hakerem are all "products of the ground" (גידולי קרקע), whereas basar b'chalav is not. Perhaps the prohibition of benefit only applies to products of the ground. The Gemara delves into the rules of deriving laws (לימודים). If one derives a law from a single source (חדא מחדא), it can only be broken by a strong counter-argument (קולא וחומרא פרחינן), meaning showing a leniency in the source that doesn't apply to the derived case, or a stringency in the source that doesn't apply to the derived case. However, a weak counter-argument (קול דהו) cannot break it. If one derives from two sources (חדא מתרתי), it is a stronger derivation, and even a weak counter-argument can break it. But if one derives from three sources (חדא מתלת), it is so strong that even a weak counter-argument cannot break it. Since the Gemara learns the prohibition of benefit for basar b'chalav from three sources (orlah, chametz, kil'ei hakerem) in a sequential manner, without needing to find a common denominator (מעט סעד), the "products of the ground" argument, being a weak counter-argument (קול דהו) that doesn't introduce a halachic difference, cannot break this derivation.
The Gemara then clarifies the nature of kil'ei hakerem. The opinion of Isi ben Yehuda is that kil'ei hakerem becomes forbidden from the moment the seeds take root, not when they are merely placed in the ground. This means the seeds themselves had a period of permissibility before rooting. This is crucial for the comparison to chametz b'Pesach, which also had a period of permissibility. The Gemara raises a question from a case of a flowerpot with a hole (עציץ נקוב) placed over a vineyard. If a plant is growing in the pot and draws nutrients from the vineyard, it becomes kil'ei hakerem. The Gemara discusses whether the original plant in the pot becomes forbidden, or only the subsequent growth. This depends on whether the seeds were planted together from the inception (in which case the seeds themselves become forbidden upon rooting) or if an already growing plant was later introduced to the vineyard (in which case only the new growth becomes forbidden). This distinction is derived from two verses: one implying the "seed" (זרע) becomes holy (forbidden), and another implying only the "filling" or "growth" (מלאה) becomes holy.
Finally, the Gemara presents a different opinion that basar b'chalav is forbidden for consumption but permitted for benefit. This view draws a comparison (גזירה שווה) between basar b'chalav and terefah (an animal with a fatal defect). Just as terefah is forbidden for consumption but permitted for benefit, so too basar b'chalav would be forbidden for consumption but permitted for benefit. This highlights the various approaches and debates within the Gemara regarding the precise halachic status and derivation of basar b'chalav.