Yoma 81B

הוא גופיה שבת איקרי, דכתיב: ״תשבתו שבתכם״. בשלמא רב פפא לא אמר כרב אחא בר יעקב ⁠— דקרא דכתיב בגופיה עדיף. אלא רב אחא בר יעקב, מאי טעמא לא אמר כרב פפא?

Yom Kippur itself is called “Shabbat,” as it is written: “From evening until evening, you should rest on your Shabbat” (Leviticus 23:32). The Talmud compares the various opinions. Granted, Rav Pappa did not say as Rav Aḥa bar Ya’akov did because a verse that is written about the matter itself is preferable to a verbal analogy. But what is the reason that Rav Aḥa bar Ya’akov did not state his opinion in accordance with the opinion of Rav Pappa?

מיבעי ליה לכדתניא: ״ועניתם את נפשותיכם בתשעה לחודש״. יכול יתחיל ויתענה בתשעה ⁠— תלמוד לומר: ״בערב״. אי בערב ⁠— יכול משתחשך? תלמוד לומר: ״בתשעה״. הא כיצד? מתחיל ומתענה מבעוד יום, מכאן שמוסיפין מחול על הקודש.

The Talmud answers: He requires this verse of “keep your Shabbat” for that which was taught in a baraita: The verse states: “And you should afflict your souls on the 9th day of the month at evening, from evening until evening, you should rest on your Shabbat” (Leviticus 23:32). One might have thought that one should start to afflict oneself on the 9th of Tishrei; therefore, the verse states “at evening.” If the Torah had stated only “at evening,” one might have thought that the fast starts only when darkness falls; therefore, the verse states “on the 9th,” implying that one begins to fast on the 9th of Tishrei. How can these verses be reconciled? One begins to fast while it is still daytime; from here it is derived that one sanctifies and extends from the non-sacred weekday to the sacred day of Yom Kippur.

ואין לי אלא בכניסתו, ביציאתו מנין ⁠— תלמוד לומר: ״מערב עד ערב״. ואין לי אלא יום הכפורים, (ימים טובים) מניין ⁠— תלמוד לומר: ״תשבתו״. אין לי אלא (ימים טובים, שבתות) מנין ⁠— תלמוד לומר: ״שבתכם״. הא כיצד? כל מקום שנאמר שבות, (מכאן ש)מוסיפין מחול על הקודש.

I have derived only that one must add time at the beginning of Yom Kippur. From where do I derive that one adds time at the conclusion of Yom Kippur? The verse states: “From evening until evening” (Leviticus 23:32), implying that one adds at the end as well, just as he does at the beginning. And I have derived only the mitzva of adding to Yom Kippur; from where is it derived that one must also sanctify and append time before and after Festivals? The verse states: “You should rest” (Leviticus 23:32), to teach that this rule applies even to Festivals, on which one is commanded to rest. I have derived only that one adds an extension to Festivals; from where do I derive that one must also sanctify and append to Shabbatot? The verse states: “Your Shabbat” (Leviticus 23:32). How so? Every place the term: Rest [shevut] is stated, it teaches from here that one sanctifies and appends from the non-sacred weekday to the sacred.