Talmud - Shabbat 114b שבת קי״ד ב׳

When I was in Babylonia, I said with regard to that which was taught in a baraita: If Yom Kippur occurred on Shabbat eve, they would not sound the shofar as they did every Friday to herald the start of Shabbat; and if Yom Kippur occurred at the conclusion of Shabbat, they would not recite havdala to mark the end of the sanctity of Shabbat and the start of the sanctity of Yom Kippur, is a statement accepted by all. When I went to Eretz Yisrael, I found Yehuda, son of Rabbi Shimon ben Pazi, who sat and said: This baraita is in accordance with the opinion of Rabbi Akiva, as it equates the sanctity of Yom Kippur with that of Shabbat. As, if you say that it is in accordance with the opinion of Rabbi Yishmael, then, since Rabbi Yishmael said that fats from Shabbat are offered on Yom Kippur, let them sound the shofar so that the priests will know that the fats from Shabbat are offered on Yom Kippur and they may begin offering them (Rav Hai Gaon). And I said to him: You cannot prove this from here, because priests are vigilant and can be trusted to know this on their own, and there is no need to sound the shofar.

Mar Kashisha, the son of Rav Ḥisda, said to Rav Ashi: Do we say that priests are vigilant in that regard? Didn’t we learn in a mishna that three blasts were sounded in the Temple on Friday to stop the people from work, and three more were sounded to demarcate between sacred and profane? Apparently, even priests required the blasts to alert them to the beginning and end of Shabbat. The Gemara answers: As Abaye said in a different context, that certain matters were undertaken for the rest of the people in Jerusalem, so too here, these blasts were sounded for the rest of the people in Jerusalem and not for the priests.

The Gemara asks: In any event, Let them sound the shofar so that they will know that trimming the vegetables, i.e., removing the leaf heads from vegetables in preparation for cutting them, is permitted from the late afternoon and onward. On Yom Kippur, it is permitted, starting at a certain point of the day, to prepare vegetables for the meal following the fast. However, this is not permitted on Shabbat, when it is prohibited to perform any action in preparation for the weekdays after Shabbat. Rav Yosef said: This is because a rabbinic prohibition [shevut] is not overridden in order to permit another action. Although sounding the shofar is not prohibited by Torah law on Shabbat, it is prohibited by rabbinic law on Shabbat and Yom Kippur, and this prohibition is not overridden to permit another action.

And Rav Sheisha, son of Rav Idi, said: The Sages permitted doing so for an immediate rabbinic prohibition, e.g., sounding the shofar to permit prohibited actions immediately. They did not permit doing so for a more remote rabbinic prohibition, such as trimming vegetables, which is allowed only beginning late in the afternoon, several hours after the start of Yom Kippur (Rabbeinu Ḥananel).

The Gemara asks: And did they permit doing so for an immediate rabbinic prohibition? Didn’t we learn in a mishna that if a Festival occurs on Shabbat eve, one sounds the shofar to announce that Shabbat has begun, but one does not recite havdala over wine to mark the conclusion of the Festival, because the sanctity of Shabbat is greater than the sanctity of the Festival? And if a Festival occurs at the conclusion of Shabbat, one recites havdala to demarcate between the sanctity of Shabbat and the sanctity of the Festival, but one does not sound the shofar. And why does one not sound the shofar? Let them sound the shofar at the beginning of the Festival, so that people will know that slaughtering is permitted immediately on the Festival, although it was prohibited on Shabbat. Rather, it is clear that this must be explained in accordance with the opinion of Rav Yosef, who says that a rabbinic prohibition is not overridden to permit the performance of actions that were prohibited.

With regard to trimming vegetables on Yom Kippur, the Gemara cites that which Rabbi Zeira said that Rav Huna said, and some say Rabbi Abba said that Rav Huna said: If Yom Kippur occurs on Shabbat, trimming vegetables is prohibited. Rav Mana said: It was taught in a baraita: From where is it derived that on Yom Kippur that occurs on Shabbat trimming vegetables is prohibited? The verse states: “A solemn rest [shabbaton], a holy Shabbat unto the Lord” (Exodus 16:23), which means that there is an obligation to issue a rabbinic prohibition on this day. Issue a rabbinic prohibition for what activity? If you say this refers to prohibiting actual labor, isn’t it written explicitly: “But the seventh day is Shabbat for the Lord your God; you shall not perform any labor” (Exodus 20:9)? Rather, does it not refer to trimming vegetables, which is prohibited on Shabbat even though it is not a full-fledged prohibited labor? The Gemara concludes: Indeed, learn from it that trimming vegetables is prohibited.

Rabbi Ḥiyya bar Abba said that Rabbi Yoḥanan said: If Yom Kippur occurs on Shabbat, trimming vegetables is permitted. The Gemara raised an objection from what we learned in the baraita cited earlier: From where is it derived that on Yom Kippur that occurs on Shabbat trimming vegetables is prohibited? The verse states: “A solemn rest [shabbaton], a holy Shabbat unto the Lord” (Exodus 16:23), which means that there is an obligation to issue a rabbinic prohibition on this day. Issue a rabbinic prohibition for what activity? If you say this refers to prohibiting actual labor, isn’t it written explicitly: “But the seventh day is Shabbat for the Lord your God; you shall not perform any labor” (Exodus 20:9)? Rather, is it not referring to trimming vegetables, which is prohibited on Shabbat? The Gemara answers: No, that is not; rather, solemn rest actually refers to labor. It is a positive commandment to rest on Shabbat. Although the verse says explicitly: “But the seventh day is Shabbat for the Lord your God; you shall not perform any labor,” this adds that one who performs a prohibited labor violates both a positive mitzva and a prohibition.

It was taught in a baraita in accordance with the opinion of Rabbi Yoḥanan: If Yom Kippur occurs on Shabbat,

Traduction : The William Davidson digital edition of the Koren Noé Talmud, with commentary by Rabbi Adin Even-Israel Steinsaltz.

Shabbat 114b examines whether shofar blasts marked Yom Kippur transitions with Shabbat, debating priestly awareness of sacrificial timing rules.