Chullin 96a

ולא מהדרינן בטביעות עינא השתא דשמעתינהו להני שמעתתא אמינא טביעות עינא עדיפא but we do not return a lost item to one who claims to be its owner based solely on visual recognition. But now that I have heard these statements pertaining to meat or sky-blue wool that were obscured from sight and then permitted based upon visual recognition, I say that visual recognition is preferable to a distinguishing mark.

דאי לא תימא הכי היאך סומא מותר באשתו ובני אדם איך מותרין בנשותיהן בלילה אלא בטביעות עינא דקלא הכא נמי בטביעות עינא Furthermore, one must hold that sensory recognition is reliable even without identifying marks, for if you do not say so, how is it that a blind man permitted to engage in sexual intercourse with his wife despite the fact that he cannot identify her by means of her identifying marks? And similarly, how are any men permitted to engage in intercourse with their wives at night, when it is dark and they cannot see their wives’ identifying marks? Rather, one must say that they identify their wives based on voice recognition. Here too, in these cases of lost meat and sky-blue wool, they remain permitted based on visual recognition.

אמר רב יצחק בריה דרב משרשיא תדע דאילו אתו בתרי ואמרי פלניא דהאי סימניה והאי סימניה קטל נפשא לא קטלינן ליה ואילו אמרי אית לן טביעות עינא בגויה קטלינן ליה Rav Yitzḥak, son of Rav Mesharshiyya, said: You can know that visual recognition is preferable to a distinguishing mark, because if two witnesses come to court and say: So-and-so, who has this distinguishing mark and that distinguishing mark, killed a person, we would not kill him based on this testimony. But if the two witnesses say: We have visual recognition of him, and they confirm that the accused individual committed murder, we kill him based on their testimony.

אמר רב אשי תדע דאילו א"ל איניש לשלוחיה קרייה לפלניא דהאי סימניה והאי סימניה ספק ידע ליה ספק לא ידע ליה ואילו אית ליה טביעות עינא בגויה כי חזי ליה ידע ליה: Rav Ashi said: You can know that visual recognition is preferable to a distinguishing mark, because if a man says to his agent: Call so-and-so, who has this distinguishing mark and that distinguishing mark, it is uncertain whether the agent will recognize him and know whom to call or whether he will not know him. But if he has visual recognition of him, when he sees him he will know it is him.

מתני׳ הנוטל גיד הנשה צריך שיטול את כולו ר' יהודה אומר כדי לקיים בו מצות נטילה MISHNA: One who removes the sciatic nerve must scrape away the flesh in the area surrounding the nerve to ensure that he will remove all of it. Rabbi Yehuda says: Scraping is not required; it is sufficient to excise it from the area above the rounded protrusion in order to thereby fulfill the mitzva of removal of the sciatic nerve.

האוכל מגיד הנשה כזית סופג ארבעים אכלו ואין בו כזית חייב אכל מזה כזית ומזה כזית סופג שמונים ר' יהודה אומר אינו סופג אלא ארבעים: One who eats an olive-bulk of the sciatic nerve incurs forty lashes. If one eats an entire sciatic nerve and it does not constitute an olive-bulk, he is nevertheless liable to receive lashes, because a complete sciatic nerve is a complete entity. If one ate an olive-bulk from this sciatic nerve in the right leg, and an olive-bulk from that sciatic nerve in the left leg, he incurs [sofeg] eighty lashes. Rabbi Yehuda says: He incurs only forty lashes, for eating the olive-bulk from the right leg, and he is exempt for eating the olive-bulk from the left leg.

גמ׳ בר פיולי הוה קאי קמיה דשמואל וקא מנקר אטמא הוה קא גאים ליה א"ל חות ביה טפי השתא לא חזיתך ספיתא לי איסורא GEMARA: A man known as bar Peyoli was standing before Shmuel and was removing the sciatic nerve from the leg of an animal. He was cutting out the nerve without scraping away the surrounding flesh, in accordance with the opinion of Rabbi Yehuda. Shmuel said to him: Go down further and scrape away the flesh in order to remove the entire nerve. Now, if I would not have seen you and instructed you in the process of removing the sciatic nerve, you would have fed me forbidden meat.

אירתת נפל סכינא מידיה א"ל לא תירתת דאורי לך כרבי יהודה אורי לך Bar Peyoli became afraid due to Shmuel’s rebuke and the knife fell from his hand. Shmuel said to him: Do not be afraid. I do not think that you are an ignoramus or a wicked person. You are removing the sciatic nerve as you were taught; the person who taught you must hold in accordance with the opinion of Rabbi Yehuda, and this is how he taught you to remove the sciatic nerve. But I hold that the entire sciatic nerve must be removed, in accordance with the opinion of the first tanna.

אמר רב ששת מאי דשקל בר פיולי דאורייתא לרבי יהודה מכלל דשייר דרבנן לר' יהודה אלא דאורי ליה כמאן אורי ליה Rav Sheshet said in explanation of this incident: That which bar Peyoli removed was the section of the sciatic nerve one is required to remove by Torah law according to the opinion of Rabbi Yehuda. The Gemara asks: Based upon this statement, one can derive by inference that he left behind the section of the sciatic nerve one is required to remove by rabbinic law according to the opinion of Rabbi Yehuda. But if so, in accordance with whose opinion did the person who taught him how to remove the sciatic nerve teach him? Even according to Rabbi Yehuda he would have transgressed a rabbinic prohibition.

אלא אמר רב ששת מאי דשקל בר פיולי דאורייתא ומאי דשייר דרבנן לר"מ דאי רבי יהודה אפילו מדרבנן שרי: Rather, Rav Sheshet said: That which bar Peyoli removed was the section of the sciatic nerve that is forbidden by Torah law. And that which he left over is forbidden by rabbinic law according to the opinion of Rabbi Meir, as explained above (92b) in a baraita; as if one were to follow the opinion of Rabbi Yehuda, the section that bar Peyoli left over is permitted even by rabbinic law.

האוכל מגיד הנשה [וכו']: אמר שמואל לא אסרה תורה אלא שעל הכף בלבד שנאמר (בראשית לב, לג) על כף הירך § The mishna teaches: One who eats an olive-bulk of the sciatic nerve incurs forty lashes. Shmuel says: The Torah prohibits only the part of the sciatic nerve that is on the rounded protrusion of flesh shaped like a spoon that is near the end of the femur. This is as it is stated in the verse: “Therefore the children of Israel eat not the sciatic nerve that is upon the spoon of the thigh” (Genesis 32:33).

אמר רב פפא כתנאי אכלו ואין בו כזית חייב רבי יהודה אומר עד שיהא בו כזית Rav Pappa says: This statement of Shmuel is subject to a dispute between tanna’im, as it is taught in a baraita: If one ate the entire sciatic nerve and it did not contain an olive-bulk, he is nevertheless liable to be flogged. Rabbi Yehuda says: He is not liable unless it has a volume of at least an olive-bulk.

מ"ט דרבנן בריה (בפני עצמה) היא Rav Pappa explains how this relates to Shmuel’s statement. What is the reason for the opinion of the Rabbis, who disagree with Rabbi Yehuda? They hold that the sciatic nerve is a distinct entity. Therefore, even if one eats less than an olive-bulk it is a significant act of eating, and one is liable.

ור' יהודה אכילה כתיבה ביה ורבנן ההיא אכילה דכי אית ביה ארבעה וחמשה זיתים ואכל חד כזית מיחייב And what does Rabbi Yehuda hold? He holds that since the term: Eating, is written with regard to the sciatic nerve, and a significant act of eating is generally defined as eating an olive-bulk, one is liable only if he eats an olive-bulk. And what do the Rabbis derive from this term? That usage of the term eating indicates that in a case where the sciatic nerve contains four or five olive-bulks and one ate only one olive-bulk, he is liable. Nevertheless, if one eats the entire sciatic nerve, he is liable even if it contains less than an olive-bulk.

ורבי יהודה מאשר על כף הירך נפקא And according to Rabbi Yehuda, from where is it derived that one is liable for eating one olive-bulk of a larger sciatic nerve? He holds that it is derived from the phrase “that is upon the spoon of the thigh,” which indicates that even if one eats only the part of the sciatic nerve that is upon the spoon of the thigh, rather than the entire sciatic nerve, he is liable.

ורבנן ההוא מיבעי ליה לכדשמואל דאמר שמואל לא אסרה תורה אלא שעל כף הירך ור' יהודה הירך כתיב דכולה ירך And how do the Rabbis interpret that phrase? That phrase is necessary to teach the halakha stated by Shmuel, as Shmuel said: The Torah prohibits only the part of the sciatic nerve that is on the rounded protrusion of flesh shaped like a spoon. And what does Rabbi Yehuda hold with regard to the halakha stated by Shmuel? He derives from the fact that it is written: “The spoon of the thigh,” that the sciatic nerve of the entire thigh is forbidden, not just the part that is on the rounded protrusion of flesh shaped like a spoon.

ורבנן ההוא דפשיט איסוריה בכוליה ירך לאפוקי חיצון דלא ולעולם שעל הכף And how do the Rabbis interpret “the spoon of the thigh”? According to the Rabbis, this expression indicates that the prohibition of the sciatic nerve applies to the nerve that extends throughout the entire thigh, i.e., the inner nerve, which serves to exclude the outer nerve, which is not forbidden by Torah law; but in fact, only the part of the inner nerve that is on the protrusion of flesh shaped like a spoon is forbidden, not the entire inner nerve.

והאי כף מיבעי ליה למעוטי עוף דלית ליה כף תרי כף כתיבי: The Gemara objects: But this term “spoon” is required to exclude the sciatic nerve of a bird, which does not have a rounded protrusion on its thigh bone that can be described as the spoon of the thigh, as taught in the mishna (89b). The Gemara explains: There are two usages of the term “spoon” written in the verse, and therefore two separate halakhot can be derived from this term.

מתני׳ ירך שנתבשל בה גיד הנשה אם יש בה בנותן טעם הרי זו אסורה כיצד משערין אותה כבשר בלפת MISHNA: In the case of a thigh that was cooked with the sciatic nerve in it, if there is enough of the sciatic nerve in it to impart its flavor to the thigh, the entire thigh is forbidden for consumption. How does one measure whether there is enough sciatic nerve to impart flavor to the meat of the entire thigh? One relates to it as though the sciatic nerve were meat imparting flavor to a turnip. If meat the volume of the sciatic nerve would impart flavor to a turnip the volume of the thigh when they were cooked together, then the entire thigh is forbidden.

גיד הנשה שנתבשל עם הגידים בזמן שמכירו בנותן טעם ואם לאו כולן אסורין והרוטב בנותן טעם With regard to a sciatic nerve that was cooked with other sinews, when one identifies the sciatic nerve and removes it, the other sinews are forbidden if the sciatic nerve was large enough to impart flavor. And if he does not identify it, all the sinews are forbidden because each one could be the sciatic nerve; but the broth is forbidden only if the sciatic nerve imparts flavor to the broth.

וכן חתיכה של נבלה וכן חתיכה של דג טמא שנתבשלה עם החתיכות בזמן שמכירן בנותן טעם ואם לאו כולן אסורות והרוטב בנותן טעם: And similarly, in the case of a piece of an animal carcass or a piece of non-kosher fish that was cooked with similar pieces of kosher meat or fish, when one identifies the forbidden piece and removes it, the rest of the meat or fish is forbidden only if the forbidden piece was large enough to impart flavor to the entire mixture. And if he does not identify and remove the forbidden piece, all the pieces are forbidden, due to the possibility that each piece one selects might be the forbidden piece; but the broth is forbidden only if the forbidden piece imparts flavor to the broth.

גמ׳ אמר שמואל לא שנו אלא שנתבשל בה אבל נצלה בה קולף ואוכל עד שמגיע לגיד GEMARA: The mishna teaches that a thigh that was cooked with the sciatic nerve is forbidden if the nerve imparts flavor to the thigh. Shmuel says: The Sages taught that the thigh is entirely forbidden only when it was cooked with the sciatic nerve inside it. But if the sciatic nerve was roasted inside the thigh, one may peel away the meat and eat it until he reaches the sciatic nerve, and then he removes the nerve.

איני והאמר רב הונא גדי שצלאו בחלבו אסור לאכול אפילו מראש אזנו The Gemara challenges: Is that so? But doesn’t Rav Huna say: With regard to a kid that was roasted with its forbidden fat, it is prohibited to eat any part of the animal, even from the top of its ear? This proves that roasting, like cooking, spreads the flavor of the forbidden fat throughout the entire animal.