Daf Yomi · Expert – Beit Midrash Analysis · Standard
Chullin 58
Sugya Map
The sugya in Chullin 58a investigates the halakhic and biological parameters of offspring and eggs generated by a tereifa (a terminally damaged animal or bird).
- The Core Issue: Does an egg or fetus produced by a tereifa inherit the mother's prohibited status as a somatic extension of her body (ubbar yerekh immo / gufah hi), or does the paternal contribution from a kosher sire permit the offspring via the principle of zeh va-zeh gorem (this and that cause it)?
- The Sub-Issue: Can a tereifa animal actually conceive or survive to lay eggs? This drives the dispute between Ravina and Rav Acha bar Yaakov.
- Nafka Minot (Practical Ramifications):
- The permissibility of consuming eggs laid by a bird suspected of being a tereifa.
- The validity of sacrificing the offspring of a tereifa on the mizbe'ach (altar).
- The halakhic status of commercial eggs when systemic injuries occur in laying hens.
- Primary Sources: Chullin 58a, Mishnah Eduyot 5:1, Mishnah Bekhorot 6:4 (paralleling Bekhorot 40a), and Temurah 30b.
Full Experience in the App
Listen. Chat. Go deeper.
Audio playback, interactive chevruta, Hebrew tools, and every daily learning track — only in Derekh Learning.
Text Snapshot
The Gemara on Chullin 58a:1 states:
"אמר אמימר: שיחלא קמא אסירא, מכאן ואילך — הוה ליה זה וזה גורם, ומותר."
- Lexical Nuance: The term shichala (שיחלא) is translated by Rashi as poste in Old French, meaning "laying" or "clutch" of eggs.[^1]
- Grammatical Nuance: In the ensuing challenge, Rav Ashi quotes the Mishnah in Eduyot:[^2] "ומודים בביצת טרפה שהיא אסורה מפני שגדלה באיסור." Rav Ashi notes the verb gadeleh (גדלה - "grew"), which implies ongoing development in a state of prohibition. If the Mishnah referred only to the first clutch, which was already fully formed inside the bird at the onset of its tereifa status, it should have employed the term gemarah (גמרה - "completed") rather than gadeleh (grew). Ameimar is forced to emend the text of the Mishnah to "גמרה" to sustain his position.[^3]
[^1]: Rashi on Chullin 58a:1:1, s.v. "דשיחלא קמא". [^2]: Mishnah Eduyot 5:1. [^3]: Chullin 58a:10, s.v. "אמר ליה אמימר התם בדשיחלא קמא".
Readings
Rashi vs. Tosafot: The Mechanics of Zeh va-Zeh Gorem
Rashi explains that for any eggs fertilized after the bird becomes a tereifa, the kosher male partner and the tereifa female partner serve as joint causes of the egg’s existence.[^4] Because the egg is brought about by a mixture of a permitted cause (heter) and a prohibited cause (issur), the halakhic rule of zeh va-zeh gorem mutar (this and that cause it is permitted) applies, and the egg is kosher.
[^4]: Rashi on Chullin 58a:1:2, s.v. "מכאן ואילך".
Tosafot raises a classic kushya from Ketubot 111b regarding the breeding of mules.[^5] In that context, the Gemara is uncertain whether we must account for the paternal genetic contribution (chayshinan le-zar'a de-aba). If the rule of zeh va-zeh gorem always results in a permitted status, why does Rabbi Yehuda worry about the father's species contribution when cross-breeding a horse and a donkey? Why doesn't the principle of zeh va-zeh gorem simply render the offspring permitted regardless of the paternal species?
[^5]: Tosafot on Chullin 58a:1:1, s.v. "מכאן ואילך הוה ליה זה וזה גורם ומותר".
Tosafot resolves this by drawing a fundamental conceptual distinction between two types of halakhic challenges:
- The Clash of Issur and Heter: Where one cause is prohibited (tereifa) and the other is permitted (kosher), the permitted cause has the power to neutralize the prohibited cause. The issur does not possess the structural strength to override the heter when both act as equal catalysts.
- The Definition of Species (Shem Min): In the case of cross-breeding mules, we are not dealing with a conflict between an issur and a heter. Both the horse and the donkey are entirely permitted animals. Rather, we are attempting to define the ontological species identity (shem min) of the offspring for the laws of kilayim (hybridization). Species identity is an additive, essentialist definition; it is not subject to dilution or neutralization. Thus, the genetic contribution of both parents must be accounted for, and zeh va-zeh gorem cannot bypass the reality of hybrid lineage.
The Rambam's Epistemological Reading of Ravina
The Gemara presents two versions of Ameimar's statement. Rav Acha bar Yaakov's version assumes a tereifa can lay subsequent eggs, which are permitted via zeh va-zeh gorem. Ravina's version, however, asserts that a tereifa is physically incapable of laying eggs or reproducing. Therefore, if a bird suspected of being a tereifa lays subsequent eggs, it retroactively proves that the initial diagnosis of tereifa was incorrect.
The Rambam codifies the law in accordance with the second, more stringent version of Ravina:[^6]
"יראה לי שאין חוששין לשיחלא קמא... אלא הרי אלו מותרות."
[^6]: Rambam, Mishneh Torah, Hilkhot Ma'akhalot Asurot 3:12.
The Rambam rules that if a bird is a safek tereifa (uncertainly damaged) and we isolate it, any subsequent egg-laying serves as a retroactive validation of the bird's systemic health. It does not merely permit the second clutch; it retroactively permits the first clutch as well.
The Maggid Mishneh notes that the Rambam’s ruling hinges on a unique epistemological mechanism.[^7] The subsequent egg-laying does not create a new halakhic status; rather, it unveils the reality (giley milta למפרע) that the bird was never a tereifa to begin with. This highlights a fundamental shift from physical causation to retroactive legal evidence (berur).
[^7]: Maggid Mishneh on Hilkhot Ma'akhalot Asurot 3:12.
The Ran and Rashba: Ubbar Yerekh Immo vs. Gufah Hi
The Gemara discusses the dispute between Rabbi Eliezer and Rabbi Yehoshua regarding whether the offspring of a tereifa may be sacrificed on the altar.[^8] According to Ravina's version, this dispute is based on whether ubbar yerekh immo (the fetus is considered the thigh of its mother). Rabbi Eliezer holds yerekh immo, meaning the fetus is an organ of the mother and becomes a tereifa the moment she does. Rabbi Yehoshua holds lav yerekh immo, treating the fetus as an independent entity that remains kosher.
[^8]: Chullin 58a:6, s.v. "ולד טרפה רבי אליעזר אומר לא יקרב".
Yet, regarding the first clutch of eggs (shichala kama), even Rabbi Yehoshua concedes they are prohibited because they are considered "her actual body" (gufah hi).
The Ran asks: If Rabbi Yehoshua holds ubbar lav yerekh immo because the fetus has its own independent life force, why does he view the egg in the oviduct as gufah hi?[^9] After all, the egg will eventually hatch into an independent chick.
[^9]: Ran on Chullin 58a (Rif daf 22b), s.v. "ומודים בביצת טריפה".
The Ran resolves this by differentiating between the biological mechanics of a mammalian fetus and an avian egg:
- The Fetus: A mammalian fetus possesses its own chayut (independent life force and blood circulation). Although it is nourished by the mother, it is structurally distinct. Therefore, Rabbi Yehoshua can argue ubbar lav yerekh immo.
- The Egg: An egg inside the oviduct, during its initial stages (shichala kama), is merely a collection of accumulated nutrients (yolk and albumen) secreted from the mother's somatic tissue. It does not possess any independent life force or embryonic form until it is laid and incubated. Consequently, while inside the mother, it is not an independent organism; it is literally a piece of the mother's flesh—gufah hi.
The Rogatchover Gaon: Tzurah vs. Chomer
In his Tzofnat Paneach, the Rogatchover Gaon analyzes this distinction using Aristotelian-Maimonidean terminology: tzurah (form) and chomer (matter).[^10]
[^10]: Tzofnat Paneach, Hilkhot Ma'akhalot Asurot 3:11.
The Rogatchover explains that a mammalian fetus, even while in the womb, has already acquired its own independent tzurah (the form of a distinct animal). Its physical connection to the mother is merely one of chomer (nutritional matter). Because halakhic identity is determined by the tzurah, Rabbi Yehoshua rules that the fetus is not yerekh immo.
The egg in the oviduct, however, has not yet developed its own tzurah. It is pure chomer of the mother, shaped and bounded only by the mother's internal organs. Because it lacks an independent tzurah, its halakhic identity is entirely subsumed under the mother's tzurah. When the mother becomes a tereifa, this status completely saturates the egg's formless matter, rendering it permanently prohibited.
Friction
Kushya: Why Doesn't Zeh va-Zeh Gorem Permit the First Clutch?
If the rule of zeh va-zeh gorem is a basic physical and halakhic principle of mixture, why can it not be applied to permit the first clutch of eggs (shichala kama)? Even if the egg was inside the mother when she became a tereifa, it was still fertilized by a kosher male. Why doesn't the paternal contribution act as a permitting cause (gorem de-heteira) to neutralize the maternal issur?
Terutz: The Temporal-Somatic Barrier
The Brisker Rav (Rav Velvel Soloveitchik) resolves this by analyzing the temporal mechanics of issur acquisition.[^11]
[^11]: Chiddushei Rabbeinu Griz Halevi, Chullin 58a.
The principle of zeh va-zeh gorem applies only when the creation or growth of an entity occurs through the simultaneous operation of two forces (e.g., when a plant grows from both forbidden fertilizer and permitted soil). In such cases, the final product is born out of a dual partnership, and the issur never has sole dominion over the object.
However, in the case of the shichala kama, the egg was already fully formed as a somatic part of the mother's body before the onset of the tereifa status, or it became tereifa as a direct part of the mother's flesh. At the moment the mother was rendered a tereifa, the egg—which was gufah hi (her actual body)—instantly acquired the status of tereifa as an inherent somatic reality (issur guf).
Once an object is saturated with an inherent somatic issur, subsequent fertilization or growth cannot retroactively dismantle that status. Zeh va-zeh gorem can prevent a prohibition from taking hold during the developmental stage, but it lacks the chemical or halakhic power to undo an already established, somatic issur.
Kushya: The 12-Month Rule vs. Scientific Reality
The Gemara asserts as a biological axiom that a tereifa animal cannot survive for twelve months, and a boneless creature cannot survive a single year.[^12]
[^12]: Chullin 58a:9, s.v. "הלכתא בזכר כל יב"ח".
Modern veterinary medicine, however, demonstrates that animals with many of the anatomical defects classified by Chazal as tereifot (such as certain lung punctures or missing limbs) can indeed survive past twelve months, and even reproduce under controlled laboratory conditions. How do we reconcile this empirical reality with the absolute truth of Chazal's halakhic categories?
Terutz: The Immutable Halakhic Taxonomy
The Rashba addresses this tension in a famous teshuvah:[^13]
"אל תתמה על שהרופאים אומרים... שאין לנו אלא מה שמנו חכמים."
[^13]: Shut HaRashba, vol. 1, signon 98.
The Rashba establishes that the definitions of tereifot are not dynamic medical diagnoses subject to the shifting understandings of science. Rather, they are immutable halakhic categories given as a halakha le-Moshe mi-Sinai.
The Chazon Ish expands on this concept, explaining that the Torah established a fixed taxonomy based on the natural order prevalent at the time of the Torah's giving.[^14] Even if subsequent generations witness changes in nature (nishtanu ha-teva'im) or develop advanced veterinary technologies that can sustain a terminally ill animal indefinitely, the halakhic status remains unchanged. The 12-month rule is a legal threshold (gezerat hakatuv), not an empirical prediction. If an animal possesses one of the eight categories of tereifot enumerated in Chullin 42b, it is halakhically dead (ke-man de-katila damya), regardless of its actual biological longevity.
[^14]: Chazon Ish, Yoreh Deah 5:3.
Intertext
Parallel 1: The Asherah Fertilizer in Avodah Zarah
The mechanics of zeh va-zeh gorem in our sugya closely parallel the discussion in Avodah Zarah 48b. There, the Gemara analyzes a field that was fertilized using the ashes of an Asherah tree (which is strictly forbidden for benefit, assur be-hana'ah). The Gemara rules:
"זה וזה גורם — מותר."
Because the crop's growth is caused by both the forbidden fertilizer (issur) and the permitted soil (heter), the crop is permitted for consumption.
The Acharonim compare these two cases to understand the limits of gorem.[^15] In the case of the Asherah fertilizer, the forbidden element acts merely as an external catalyst (nourishment). In our sugya in Chullin, the forbidden element is a genetic parent (generation).
[^15]: Kehillat Yaakov, Chullin, siman 32.
The fact that zeh va-zeh gorem is effective even in genetic generation—where the physical substance of the mother is directly transferred to the offspring—demonstrates that halakha does not trace material lineage when a permitting cause is simultaneously present. The heter of the father's seed structurally breaks the chain of maternal issur.
Parallel 2: The Fetus of a Sanctified Offering in Temurah
The debate between Rabbi Eliezer and Rabbi Yehoshua regarding ubbar yerekh immo is also the central focus of Temurah 30b. If a person consecrates a pregnant animal as an offering (kedushat haguf), does the consecration automatically extend to the fetus?
- If we say ubbar yerekh immo, the fetus is consecrated as part of the mother's body.
- If we say ubbar lav yerekh immo, the fetus is a separate entity and remains unconsecrated unless specifically designated.
This parallel demonstrates that the question of maternal-fetal identity is a unified metaphysical problem across all areas of halakha, bridging the laws of kosher slaughter (kodshim) and temple sacrifices (tereifot).
Psak/Practice
Codex: Shulchan Aruch, Yoreh Deah 86:3–4
The Shulchan Aruch codifies the practical halakha as follows:[^16]
- The Eggs of a Definite Tereifa: Any eggs found inside a bird that has been slaughtered and discovered to be a tereifa are strictly prohibited, even if they are fully formed with a hard shell.[^17]
- The Eggs of a Safek Tereifa: If a living bird is suspected of being a tereifa, we must isolate it. If it lays a clutch of eggs and then ceases to lay, the eggs are prohibited. However, if it continues to lay a second clutch, it is retroactively proven that the bird was healthy, and both clutches are permitted for consumption.[^18]
[Bird Suspended as Safek Tereifa]
|
(Isolate Bird)
|
(Lays First Clutch)
|
+----------------+----------------+
| |
(Does NOT Lay Again) (Lays Second Clutch)
| |
[First Clutch Prohibited] [Retroactively Proven Kosher]
|
[Both Clutches Permitted]
[^16]: Shulchan Aruch, Yoreh Deah 86:3. [^17]: Shulchan Aruch, Yoreh Deah 86:3, based on Ravina's view. [^18]: Shulchan Aruch, Yoreh Deah 86:4.
Modern Industrial Application
In modern commercial egg production, laying hens are kept in large flocks where minor bone fractures or internal injuries are statistically common. Does this raise a concern of safek tereifa for all commercial eggs?
Contemporary poskim, including Rav Moshe Feinstein, rule that we do not need to worry about this.[^19] Halakha operates on the principle of rov (majority) as established in Chullin 11a. Since the vast majority of hens in any given flock are healthy and not tereifot, we apply the rule of kol de-parish mi-rubba parish (anything that separates, separates from the majority). Any individual egg purchased in a store is halakhically presumed to come from a kosher bird, bypassing the stringent isolation requirements of a safek tereifa.
[^19]: Igrot Moshe, Yoreh Deah, vol. 1, siman 35.
Takeaway
The sugya of beizat tereifa reveals that halakhic identity is not merely a reflection of physical biology; it is a conceptual framework where somatic integration (gufah hi) and causal partnership (zeh va-zeh gorem) define the boundaries of kosher status.
derekhlearning.com