Rav Dimi answered Abaye: No, the mishna means that although there is not one hundred and one times as much non-sacred food as teruma, the teruma is nullified because there is one hundred times its volume of non-sacred food.
והא מדרישא במאה הוי סיפא בששים דקתני רישא להחמיר מין ומינו כיצד שאור של חטין שנפל לעיסת חטין ויש בו כדי לחמץ בין יש בו כדי להעלות במאה ואחד בין אין בו כדי להעלות במאה ואחד אסור
Abaye responded: But since the first clause states that it is nullified in one hundred times its volume, it must be that the latter clause is referring to a case where there is sixty times its volume. As the mishna (Orla 2:6) teaches in the first clause: When it is stated that the halakha is to be stringent if one type of teruma is mixed with non-sacred food of its type, how is this accomplished? For example, in a case of leaven of teruma wheat that fell into dough made of non-sacred wheat, and there is enough teruma to cause the non-sacred wheat to become leavened, whether there is enough non-sacred wheat to neutralize the teruma in one hundred and one times its volume, or whether there is not enough non-sacred wheat to neutralize the teruma in one hundred and one times its volume, the entire dough is forbidden to a non-priest.
אין בו להעלות במאה ואחד בין שיש בו כדי לחמץ בין אין בו כדי לחמץ אסור רישא וסיפא במאה
But if there is not enough non-sacred wheat to neutralize the teruma in one hundred and one times its volume, then whether there is enough teruma to cause the non-sacred wheat to become leavened or whether there is not enough teruma to cause the non-sacred wheat to become leavened, the entire dough is forbidden to a non-priest. Would you suggest that both the first clause and the latter clause are stating that the teruma is nullified in one hundred times its volume?
לא רישא במאה וחד וסיפא במאה
Rav Dimi answered: No. The first clause is referring to a case where the teruma is mixed with one hundred and one times its volume of non-sacred food, and the latter clause is referring to a case where the teruma is mixed with one hundred times its volume of non-sacred food.
וכי יש בו כדי לחמץ במאה וחד אמאי לא בטיל אישתיק
Abaye asked Rav Dimi: If so, when the mishna states that if there is enough teruma to cause the non-sacred wheat to become leavened the entire mixture is forbidden to non-priests, why is that the case? If leaven is mixed with one hundred and one times its volume of non-sacred wheat it will have no leavening effect, so why is it not nullified? Rav Dimi did not have an answer and was silent.
אמר ליה דלמא שאני שאור דחימוצו קשה אמר ליה אדכרתן מילתא דאמר רבי יוסי בר' חנינא לא כל השיעורין שוין שהרי ציר שיעורו קרוב למאתים דתנן דג טמא צירו אסור רבי יהודה אומר רביעית בסאתים
Abaye said to him: Perhaps leaven is different, because its leavening properties are potent, and there are some forms of leaven that can have an effect on such a large quantity of dough. Rav Dimi said to him: You reminded me of a matter that Rabbi Yosei, son of Rabbi Ḥanina, said: Not all the measures are equal, because the measure required in order to nullify non-kosher fish brine is close to two hundred times its volume. As we learned in a mishna (Terumot 10:8): The brine of a non-kosher fish is forbidden. Rabbi Yehuda says: A quarter-log of non-kosher fish brine renders kosher food forbidden even if it is mixed with two se’a of permitted food, which is one hundred ninety-two times as much as a quarter-log.
והאמר רבי יהודה מין במינו לא בטיל שאני ציר דזיעה בעלמא הוא:
The Gemara asks: How can Rabbi Yehuda say that fish brine is nullified at all? Doesn’t Rabbi Yehuda say that a type of food mixed with food of its own type is not nullified? The Gemara answers: Brine is different because it is merely sweat, i.e., it does not have the halakhic status of the fish itself.
כיצד משערינן: אמר רב הונא כבשר בראשי לפתות מתני' דלא כהאי תנא דתניא רבי ישמעאל בנו של רבי יוחנן בן ברוקה אומר אין בגידין בנותן טעם
§ The mishna (96b) teaches: 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 and the thigh were a turnip. If the meat would impart flavor to the turnip when they were cooked together, then the entire thigh is forbidden. The Gemara states that Rav Huna says: The mishna means that it is measured like meat cooked in a pot with turnip heads. The Gemara notes that the mishna is not in accordance with the opinion of this tanna, as it is taught in a baraita: Rabbi Yishmael, son of Rabbi Yoḥanan ben Beroka, says: Sciatic nerves do not impart flavor at all.
ההוא דאתא לקמיה דרבי חנינא הוה יתיב רבי יהודה בר זבינא אבבא כי נפק אמר ליה מאי אמר לך אמר ליה שריא ניהליה
There was a certain man who came before Rabbi Ḥanina to ask about the status of a thigh of an animal that was cooked with its sciatic nerve, and Rabbi Yehuda bar Zevina was sitting at the gate. When the man left, Rabbi Yehuda bar Zevina said to him: What did Rabbi Ḥanina say to you? The man said to him: He permitted me to eat the thigh.
אמר ליה הדר עייליה לקמיה אמר מאן האי דקא מצער לי זיל אימא ליה למאן דיתיב אבבא אין בגידין בנותן טעם
Rabbi Yehuda bar Zevina said to him: Bring the animal before him again; perhaps he did not fully understand the question. When the man returned to Rabbi Ḥanina, Rabbi Ḥanina said: Who is this person who is bothering me? Go and say to the individual who is sitting at the gate, i.e., Rabbi Yehuda bar Zevina: Sciatic nerves do not impart flavor. Consequently, he can remove the sciatic nerve and the rest of the meat is permitted.
כי אתו לקמיה דרבי אמי משדר להו לקמיה דרבי יצחק בן חלוב דמורי בה להיתירא משום דרבי יהושע בן לוי וליה לא סבירא ליה והלכתא אין בגידין בנותן טעם:
When people would come before Rabbi Ami to ask about the halakha of a thigh that was cooked with the sciatic nerve inside, he would send them before Rabbi Yitzḥak ben Ḥalov, who would rule leniently about this issue and say that is was permitted, in the name of Rabbi Yehoshua ben Levi. Rabbi Ami himself did not hold accordingly, but he did not wish to rule stringently for others. And the halakha is that sciatic nerves do not impart flavor at all.
גיד הנשה שנתבשל: וליבטול ברובא
§ The mishna states (96b): 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. The Gemara challenges: Let the sciatic nerve be nullified by a simple majority.