דאם כן מפסדת לה לקמייתא התם מאי טעמא קא מכשרת דכי נפקא חיותא בהכשירה קא נפקא הכא נמי כי נפקא חיותא בהגרמה קא נפקא

as, if you retract your statement, you repudiate the first ruling that you stated with regard to a case where one diverted the knife and cut one-third of the windpipe, and then cut one-third properly, and then diverted and cut the final one-third. There, what is the reason that you deemed the slaughter valid? The reason is that when life left the animal with the cutting of the second third of the windpipe, it left the animal in the course of valid slaughter. Based on that reasoning, here too, when life left the animal with the cutting of the second third of the windpipe, it left the animal in the course of diverting the knife, and the slaughter is invalid.

איקלע רב נחמן לסורא בעו מיניה שחט שליש והגרים שליש ושחט שליש מהו אמר להו לאו היינו דרבי אלעזר בר מניומי דאמר רבי אלעזר בר מניומי שחיטה העשויה כמסרק כשרה

Rav Naḥman happened to come to Sura, where they asked him: If one cut one-third of the windpipe properly, and then diverted the knife and cut one-third, and then cut the final one-third of the windpipe properly, what is the halakha? He said to them: Isn’t that the halakha stated by Rabbi Elazar bar Minyumi, as Rabbi Elazar bar Minyumi says: Slaughter that is performed like the teeth of a comb, which are jagged, is valid.

ודלמא במקום שחיטה במקום שחיטה מאי למימרא מהו דתימא בעינן שחיטה מפורעת וליכא קא משמע לן

The Gemara objects: And perhaps Rabbi Elazar bar Minyumi stated his halakha only when the slaughter goes up and down within the proper place of slaughter. The Gemara asks in response: Within the proper place of slaughter, what is the purpose of stating it? Clearly the slaughter is valid in that case. The Gemara explains: Lest you say that we require slaughter that is clear and straight, and slaughter that is jagged is not straight, therefore, Rabbi Elazar bar Minyumi teaches us that nevertheless, the slaughter is valid.

(סימן בכד)

The Gemara cites a mnemonic for the order of the Sages in the following discussion: Beit for Rabbi Abba; kaf for Rav Kahana; dalet for Rav Yehuda.

יתיב רבי אבא אחוריה דרב כהנא ויתיב רב כהנא קמיה דרב יהודה ויתיב וקאמר שחט שליש והגרים שליש ושחט שליש מהו אמר ליה שחיטתו כשרה

Rabbi Abba sat behind Rav Kahana and Rav Kahana sat before Rav Yehuda, and he sat and said to Rav Yehuda: If one cut one-third of the windpipe properly, and then diverted the knife and cut one-third, and then cut the final one-third of the windpipe properly, what is the halakha? Rav Yehuda said to Rav Kahana: His slaughter is valid.

הגרים שליש ושחט שליש והגרים שליש מהו אמר ליה שחיטתו פסולה

Rav Kahana then asked: If one diverted the knife and cut one-third of the windpipe, and then cut one-third properly, and then diverted and cut the final one-third, what is the halakha? Rav Yehuda said to him: His slaughter is not valid.

שחט במקום נקב מהו אמר ליה שחיטתו כשרה

Rav Kahana then asked: If one cut in a place where there was a perforation in the front of the windpipe and continued cutting, what is the halakha? Rav Yehuda said to him: His slaughter is valid.

שחט ופגע בו נקב מהו אמר ליה שחיטתו פסולה

Rav Kahana further asked: If one cut the windpipe and after cutting half the windpipe encountered a perforation, after which point a majority of the windpipe had been cut, what is the halakha? Rav Yehuda said to him: His slaughter is not valid.

אזל רבי אבא אמרה קמיה דרבי אלעזר אזל רבי אלעזר אמרה קמיה דרבי יוחנן אמר ליה מאי שנא

Rabbi Abba went to Eretz Yisrael and stated these halakhot in the presence of Rabbi Elazar, and Rabbi Elazar went and stated these halakhot in the presence of Rabbi Yoḥanan. Rabbi Yoḥanan said to him: What is different about a case where one cut in a place where there was a perforation relative to a case where he encountered a perforation in the middle of the slaughter?

אמר ליה שחט במקום נקב נעשה כמי ששחט גוי וגמר ישראל שחט ופגע בו נקב נעשה כמי ששחט ישראל וגמר גוי קרי עליה גוי גוי

Rabbi Elazar said to him: In a case where one cut in a place where there was a perforation, it becomes like an animal that a gentile began to slaughter and a Jew completed its slaughter, in which case the slaughter is valid. In a case where one cut the windpipe and encountered a perforation, it becomes like an animal that a Jew began to slaughter and a gentile completed its slaughter, in which case the slaughter is not valid. Rabbi Yoḥanan mockingly proclaimed about him: Gentile, gentile, i. e., you merely repeat something about gentiles. Rabbi Yoḥanan did not accept the distinction.

אמר רבא שפיר קרי עליה גוי גוי בשלמא התם מדהוה ליה לישראל למשחט רובא ולא שחט כי נפקא חיותא בידא דגוי קא נפקא אלא הכא מכדי משחט שחיט מה לי במקום נקב מה לי פגע בו נקב

Rava said: Rabbi Yoḥanan did well when he proclaimed about him: Gentile, gentile. Granted, there, in the case where the gentile completed the slaughter, since a Jew was supposed to cut a majority of the windpipe and he did not cut it, when life left the animal it left by the hand of a gentile. But here, after all, he was the one who slaughtered the entire animal, and the animal was not a tereifa until this point, and so what difference is there to me if one began to cut in a place where there was a perforation and what difference is there to me if he encountered a perforation?

מתני׳ השוחט מן הצדדין שחיטתו כשרה המולק מן הצדדין מליקתו פסולה השוחט מן העורף שחיטתו פסולה המולק מן העורף מליקתו כשירה השוחט מן הצואר שחיטתו כשרה המולק מן הצואר מליקתו פסולה שכל העורף כשר למליקה וכל הצואר כשר לשחיטה נמצא כשר בשחיטה פסול במליקה כשר במליקה פסול בשחיטה

MISHNA: One who slaughters from the sides of the throat, his slaughter is valid. One who pinches the neck of a bird offering from the sides, his pinching is not valid. One who slaughters from the nape [oref] of the neck, his slaughter is not valid. One who pinches a bird offering from the nape of the neck, his pinching is valid. One who slaughters from the throat, his slaughter is valid. One who pinches a bird offering from the throat, his pinching is not valid, as the entire nape is valid for pinching and the entire throat is valid for slaughter. It is found that that which is valid for slaughter is not valid for pinching and that which is valid for pinching is not valid for slaughter.

גמ׳ מאי עורף אילימא עורף ממש מאי אריא שוחט אפילו מולק נמי ממול ערפו אמר רחמנא ולא ערפו אלא מאי עורף ממול עורף כדקתני סיפא כל העורף כשר למליקה

GEMARA: With regard to the statement in the mishna: One who slaughters an animal from the oref, its slaughter is not valid, the Gemara asks: What is the meaning of oref? If we say that the reference is to the actual occipital bone at the rear of the skull, why does this halakha apply specifically to one who slaughters from the oref? Even if one pinches a bird offering from the oref it would also not be valid, as the Merciful One states:“ Pinch off its head adjacent to its oref” (Leviticus 5:8), at the nape beneath the occipital bone, and not its oref. Rather, what is the oref mentioned in the mishna? It is adjacent to the oref, the back of the neck below the occipital bone, as it is taught in the latter clause of the mishna: The entire nape is valid for pinching.

מנהני מילי דתנו רבנן ממול ערפו מול הרואה את העורף וכן הוא אומר והוא ישב ממלי ואומר כי פנו אלי ערף ולא פנים מאי ואומר וכי תימא עורף גופיה לא ידעינן היכא דנדע מול דידיה היכא תא שמע כי פנו אלי ערף ולא פנים מכלל דעורף להדי פנים

The Gemara asks: From where are these matters derived? They are derived as the Sages taught in a baraita:

In the phrase“ adjacent to [mimmul] its oref, ” adjacent means a place that sees the oref and not the oref itself. And likewise, the verse states: “ And they reside adjacent to me [mimmuli]” (Numbers 22:5); and the verse states: “ For they have turned their oref unto Me, and not their face” (Jeremiah 2:27). The Gemara asks: What is added by the latter proof, introduced with the term: And the verse states? The Gemara answers: And if you would say, we do not know where the oref itself is, so that we will know where adjacent to it is, come and hear: “ For they have turned their oref unto Me, and not their face, ” from which it may be ascertained by inference that the oref is opposite the face, at the rear of the head.

אמרי בני רבי חייא מצות מליקה מחזיר סימנים לאחורי העורף ומולק איכא דאמרי אף מחזיר ואיכא דאמרי מחזיר דוקא

§ The sons of Rabbi Ḥiyya say: How is the mitzva of pinching of a bird offering performed? One moves the two simanim that must be severed in ritual slaughter, i. e., the windpipe and the gullet, behind the nape and pinches. There is a dispute among the Sages with regard to the meaning of the statement. There are those who say: The mitzva ab initio is to pinch through the spinal column first and then pinch the windpipe and the gullet, and one may even move the simanim to behind the nape and pinch. And there are those who say: The mitzva is specifically to move the simanim behind the nape and pinch.

ומסתברא כמאן דאמר אף מחזיר ממאי מדקתני השוחט מן העורף שחיטתו פסולה המולק מן העורף מליקתו כשרה

The Gemara notes: And it is reasonable according to the one who says: One may even move the simanim behind the nape. From where does one draw that conclusion? It is from the fact that the mishna teaches: One who slaughters from the nape of the neck, his slaughter is not valid. One who pinches from the nape of the neck, his pinching is valid.