from above too there is a membrane that should prevent the forbidden fat from flowing onto the piece of meat even if the forbidden fat is placed directly upon it. The Gemara explains: Since the hand of the slaughterer touches the upper membrane, that membrane disintegrates and the forbidden fat flows onto the meat.

§ And Rav Yehuda says that Rav says: A Torah scholar is required to learn the requisite skills to perform three matters: Writing, so that he will be able to write texts on various occasions, ritual slaughter, and circumcision. And Rav Ḥananya bar Shelamya says in the name of Rav: He must also learn to tie the knot of the phylacteries, and to recite the blessing of the grooms by heart and with the traditional intonation, and to tie ritual fringes to the corners of a garment. The Gemara notes: And the other amora, Rav Yehuda, holds that those skills are commonplace and do not require special training.

§ And Rav Yehuda says that Shmuel says: With regard to any slaughterer who does not know the halakhot of ritual slaughter, it is prohibited to eat from his slaughter. And these are the halakhot of ritual slaughter: Interrupting the slaughter, pressing the knife, concealing the knife under the windpipe or the gullet in the course of an inverted slaughter, diverting the knife from the place of slaughter, and ripping the simanim from their place before cutting them.

The Gemara asks: What is the novelty in what Rav is teaching us? We learned all of them in the mishnayot in the second chapter of this tractate, and therefore it is obvious that a slaughterer who does not know these halakhot is not qualified. The Gemara answers: No, it is necessary in a case where the slaughterer slaughtered before us twice or three times and slaughtered well. Lest you say: From the fact that he slaughtered the other animals well, this animal he also slaughtered well; therefore, Rav teaches us: Since he did not learn the halakhot, sometimes it happens that he interrupts the slaughter or presses the knife, and he does not know that he invalidated the slaughter.

§ And Rav Yehuda says that Shmuel says: The slaughterer must examine the simanim, the windpipe and the gullet, after completing the slaughter. Rav Yosef said: We learn in a mishna (32a) as well: Rabbi Shimon says: The slaughter is not valid if he interrupted the slaughter for an interval equivalent to the duration of an examination. What, is it not an interval equivalent to the duration of an examination of the simanim? Apparently, one is obligated to examine the simanim.

Abaye said to him: No, this is what Rabbi Yoḥanan says: It is an interval equivalent to the duration of an examination of the knife, as the Sages instituted that one must take the knife to be examined by a Torah scholar prior to slaughtering the animal. Rav Yosef said to him: If so, you have rendered your statement subject to circumstances, as sometimes the Torah scholar is near and sometimes the Torah scholar is far, and the time required for examination varies accordingly. Rather, it is an interval equivalent to the duration of an examination performed by a slaughterer who is a Torah scholar. In that case, the travel time is not factored, just the time of the examination, which does not vary.

The Gemara asks: If the slaughterer did not examine the simanim after completing slaughter of the animal, what is the halakha? Rabbi Eliezer ben Antigonus says in the name of Rabbi Elazar, son of Rabbi Yannai: The halakhic status of the slaughtered animal is that of a tereifa, and it is forbidden for consumption, but it does not impart impurity. It was taught in a baraita: Its halakhic status is that of an unslaughtered carcass, and it imparts impurity by means of carrying it.

The Gemara asks: With regard to what principle do they disagree? The Gemara answers: They disagree with regard to the application of the halakha stated by Rav Huna, who says: An animal during its lifetime exists with the presumptive status of prohibition, as it is prohibited to eat a living animal, and it continues to have this status even after its death until it will become known to you in what manner it was slaughtered, i.e., whether it was properly slaughtered. Once the animal was slaughtered, it exists with the presumptive status of permissibility until it will become known to you in what manner it was rendered a tereifa.

It is with regard to the application of this halakha that Rabbi Elazar, son of Rabbi Yannai, and the tanna of the baraita disagree in a case where the slaughterer did not examine the simanim after completing the slaughter. One Sage holds: Since it has not been verified that the animal was slaughtered properly, the animal exists with the presumptive status of prohibition, and since now it is dead, it assumes the status of an unslaughtered carcass and imparts impurity. And one Sage holds: With regard to the presumptive status of prohibition, we say that the animal is forbidden until it is verified that it was slaughtered properly; with regard to the presumptive status of ritual impurity we do not say that the animal is impure, as a living animal is not ritually impure.

§ The Gemara proceeds to analyze the matter itself. Rav Huna says: An animal during its lifetime exists with the presumptive status of prohibition until it will become known to you in what manner it was slaughtered. Once the animal was slaughtered, it exists with the presumptive status of permissibility until it will become known to you in what manner it was rendered a tereifa. The Gemara challenges this: And let us say that once the animal was slaughtered, it became permitted, instead of saying that it exists with the presumptive status of permissibility. The Gemara explains: This teaches us that even if a flaw developed in the animal that raises uncertainty with regard to its permitted status, it retains its presumptive status of permissibility.

As Rabbi Abba raised a dilemma before Rav Huna: If a wolf came and took the innards of a slaughtered animal, what is the halakha?

The Gemara asks: Took? In that case the innards are not there, and therefore there is no way of seeing an indication of a flaw. Rather, the dilemma is: In a case where a wolf perforated the innards of a slaughtered animal, what is the halakha? The Gemara challenges: Perforated? We see that the wolf perforated them and in that case too there is no indication of a flaw. Rather, the dilemma is: In a case where a wolf took the innards and returned them when they are perforated, what is the halakha? Are we concerned that perhaps the wolf perforated the innards in the place of a preexisting perforation and the animal was a tereifa from the outset, or is that possibility not a concern?

Rav Huna said to Rabbi Abba: One is not concerned that perhaps the wolf perforated the innards in the place of a preexisting perforation, because one relies on the presumptive status of permissibility.

Rabbi Abba raised an objection to the opinion of Rav Huna: If one saw a bird pecking at a fig or a mouse gnawing at melons,