קידוש והבדלה

מכילתא דרבי ישמעאל, מַסֶּכְתָּא דְבַחֹדֶשׁ ז׳:ז׳-ט׳

"זכור" ו"שמור", זכור מלפניו ושמור מלאחריו. מכאן אמרו: מוסיפין מחול על הקדש, משל לזאב, שהוא טורד מלפניו ומלאחריו. אלעזר בן חנניה בן חזקיה בן חנניה בן גרון אומר: "זכור את יום השבת לקדשו" תהא זוכרו מאחד בשבת, שאם יתמנה לך מנה יפה תהא מתקנו לשם שבת. רבי יצחק אומר: לא תהא מונה כדרך שאחרים מונין, אלא תהא מונה לשם שבת:

Mekhilta DeRabbi Yishmael, Tractate Bachodesh 7:7-9

"Remember" and "Keep" — Remember it beforehand and keep it afterwards — whence they ruled: We are to add from the mundane to the holy — as a wolf tears both what is before him and what is behind him. Elazar b. Chananiah b. Garon says: "Remember the Sabbath day to sanctify it": Remember it from the first day of the week, so that if you come upon a rare bit, ready it for the Sabbath. R. Yitzchak says: Do not count (the days) as others count, but count vis-à-vis the Sabbath (e.g., "Today is the fourth day of the Sabbath")

מכילתא דרבי ישמעאל, מַסֶּכְתָּא דְבַחֹדֶשׁ ז׳:י׳

"לקדשו" – לקדשו בברכה. מכאן אמרו: מקדשין על היין בכניסתו. אין לי אלא קדושה ליום, קדושה ללילה מנין? ת"ל (שמות לא יד) "ושמרתם את השבת". אין לי אלא שבת, ימים טובים מנין? תלמוד לומר (ויקרא כג ד) "אלה מועדי ה' וגו'"!

Mekhilta DeRabbi Yishmael, Tractate Bachodesh 7:10

"to sanctify it": with a blessing — whence they ruled: It is sanctified by wine (i.e., "kiddush") upon its entry. This tells me only of kiddush at night. Whence do I derive (the same for )kiddush in the daytime? From "Remember the day of Sabbath." This tells me only of (kiddush for) the Sabbath. Whence do I derive (the same for) the festivals? From (Leviticus 23:4) "These are the festivals of the L rd, which (including the Sabbath) you shall "call" (in the kiddush) in their times."

שבת ס״ט ב:ד׳

אמר רב הונא היה מהלך (בדרך או) במדבר ואינו יודע אימתי שבת מונה ששה ימים ומשמר יום אחד חייא בר רב אומר משמר יום אחד ומונה ששה במאי קמיפלגי מר סבר כברייתו של עולם ומר סבר כאדם הראשון מיתיבי היה מהלך בדרך ואינו יודע אימתי שבת משמר יום אחד לששה מאי לאו מונה ששה ומשמר יום אחד לא משמר יום אחד ומונה ששה אי הכי משמר יום אחד לששה משמר יום אחד ומונה ששה מיבעי ליה ועוד תניא היה מהלך בדרך או במדבר ואינו יודע אימתי שבת מונה ששה ומשמר יום אחד תיובתא (דרבי חייא) בר רב תיובתא

אמר רבא בכל יום ויום עושה לו כדי פרנסתו [בר מההוא יומא] וההוא יומא לימות דעביד מאתמול שתי פרנסות ודילמא מאתמול שבת הואי אלא כל יום ויום עושה לו פרנסתו אפילו ההוא יומא וההוא יומא במאי מינכר ליה בקידושא ואבדלתא אמר רבא אם היה מכיר מקצת היום שיצא בו עושה מלאכה כל היום כולו פשיטא מהו דתימא כיון דשבת לא נפיק במעלי שבתא [נמי] לא נפיק והאי אי נמי בחמשה בשבתא נפיק לישתרי ליה למיעבד מלאכה תרי יומי קא משמע לן זימנין דמשכח שיירתא ומקרי ונפיק:

Shabbat 69b:4

Rav Huna said: One who was walking along the way or in the desert, and he does not know when Shabbat occurs, he counts six days from the day that he realized that he lost track of Shabbat and then observes one day as Shabbat. Ḥiyya bar Rav says: He first observes one day as Shabbat and then he counts six weekdays. The Gemara explains: With regard to what do they disagree? One Sage, Rav Huna, held: It is like the creation of the world, weekdays followed by Shabbat. And one Sage, Ḥiyya bar Rav, held: It is like Adam, the first man, who was created on the sixth day. He observed Shabbat followed by the six days of the week. The Gemara raises an objection to the opinion of Ḥiyya bar Rav from a baraita: If a person was walking along the way and does not know when Shabbat occurs, he observes one day for every six. What, does this not mean that he counts six and then observes one day in accordance with the opinion of Rav Huna? The Gemara rejects this: No, it could also mean that he observes one day and then counts six.

ava said: The person who lost track of Shabbat and treats one day a week as Shabbat, each day he makes enough food to sustain himself, except for that day which he designated as Shabbat. The Gemara asks: And on that day let him die? Rather, it means that the day before he makes twice the amount of food that he prepared on the other days to sustain him for that day and the following day. The Gemara asks: And perhaps the day before was actually Shabbat? In that case, not only did he perform labor on Shabbat, but he also performed labor on Shabbat in preparation for a weekday. Rather, on each and every day he makes enough food to sustain himself for that day, including on that day that he designated as Shabbat. And if you ask: And how is that day which he designated as Shabbat distinguishable from the rest? It is distinguishable by means of the kiddush and the havdala that he recites on that day.

משנה תורה, הלכות שבת כ״ט:א׳-ו׳

(א) מִצְוַת עֲשֵׂה מִן הַתּוֹרָה לְקַדֵּשׁ אֶת יוֹם הַשַּׁבָּת בִּדְבָרִים שֶׁנֶּאֱמַר (שמות כ ח) "זָכוֹר אֶת יוֹם הַשַּׁבָּת לְקַדְּשׁוֹ". כְּלוֹמַר זָכְרֵהוּ זְכִירַת שֶׁבַח וְקִדּוּשׁ. וְצָרִיךְ לְזָכְרֵהוּ בִּכְנִיסָתוֹ וּבִיצִיאָתוֹ. בִּכְנִיסָתוֹ בְּקִדּוּשׁ הַיּוֹם וּבִיצִיאָתוֹ בְּהַבְדָּלָה:

(ב) וְזֶה הוּא נֹסַח קִדּוּשׁ הַיּוֹם. בָּרוּךְ אַתָּה ה' אֱלֹהֵינוּ מֶלֶךְ הָעוֹלָם אֲשֶׁר קִדְּשָׁנוּ בְּמִצְוֹתָיו וְרָצָה בָנוּ וְשַׁבַּת קָדְשׁוֹ בְּאַהֲבָה וְרָצוֹן הִנְחִילָנוּ זִכָּרוֹן לְמַעֲשֵׂה בְרֵאשִׁית תְּחִלָּה לְמִקְרָאֵי קֹדֶשׁ זֵכֶר לִיצִיאַת מִצְרָיִם כִּי בָנוּ בָחַרְתָּ וְאוֹתָנוּ קִדַּשְׁתָּ מִכָּל הָעַמִּים וְשַׁבַּת קָדְשְׁךָ בְּאַהֲבָה וּבְרָצוֹן הִנְחַלְתָּנוּ בָּרוּךְ אַתָּה ה' מְקַדֵּשׁ הַשַּׁבָּת:

(ג) וְזֶה הוּא נֹסַח הַהַבְדָּלָה. בָּרוּךְ אַתָּה ה' אֱלֹהֵינוּ מֶלֶךְ הָעוֹלָם הַמַּבְדִּיל בֵּין קֹדֶשׁ לְחל וּבֵין אוֹר לְחשֶׁךְ בֵּין יִשְׂרָאֵל לָעַמִּים וּבֵין יוֹם הַשְּׁבִיעִי לְשֵׁשֶׁת יְמֵי הַמַּעֲשֶׂה בָּרוּךְ אַתָּה ה' הַמַּבְדִּיל בֵּין קֹדֶשׁ לְחל:

(ד) עִקַּר הַקִּדּוּשׁ בַּלַּיְלָה. אִם לֹא קִדֵּשׁ בַּלַּיְלָה בֵּין בְּשׁוֹגֵג בֵּין בְּמֵזִיד מְקַדֵּשׁ וְהוֹלֵךְ כָּל הַיּוֹם כֻּלּוֹ. וְאִם לֹא הִבְדִּיל בַּלַּיְלָה מַבְדִּיל לְמָחָר וּמַבְדִּיל וְהוֹלֵךְ עַד סוֹף יוֹם שְׁלִישִׁי. אֲבָל אֵינוֹ מְבָרֵךְ עַל הָאוּר אֶלָּא בְּלֵיל מוֹצָאֵי שַׁבָּת בִּלְבַד:

(ה) אָסוּר לְאָדָם לֶאֱכל אוֹ לִשְׁתּוֹת יַיִן מִשֶּׁקָּדַשׁ הַיּוֹם עַד שֶׁיְּקַדֵּשׁ. וְכֵן מִשֶּׁיָּצָא הַיּוֹם אָסוּר לוֹ לְהַתְחִיל לֶאֱכל וְלִשְׁתּוֹת וְלַעֲשׂוֹת מְלָאכָה אוֹ לִטְעֹם כְּלוּם עַד שֶׁיַּבְדִּיל. וְלִשְׁתּוֹת מַיִם מֻתָּר. שָׁכַח אוֹ עָבַר וְאָכַל וְשָׁתָה קֹדֶם שֶׁיְּקַדֵּשׁ אוֹ קֹדֶם שֶׁיַּבְדִּיל הֲרֵי זֶה מְקַדֵּשׁ וּמַבְדִּיל אַחַר שֶׁאָכַל:

(ו) מִדִּבְרֵי סוֹפְרִים לְקַדֵּשׁ עַל הַיַּיִן וּלְהַבְדִּיל עַל הַיַּיִן. וְאַף עַל פִּי שֶׁהִבְדִּיל בַּתְּפִלָּה צָרִיךְ לְהַבְדִּיל עַל הַכּוֹס. וּמֵאַחַר שֶׁיַּבְדִּיל וְיֹאמַר בֵּין קֹדֶשׁ לְחל מֻתָּר לוֹ לַעֲשׂוֹת מְלָאכָה אַף עַל פִּי שֶׁלֹּא הִבְדִּיל עַל הַכּוֹס. וּמְבָרֵךְ עַל הַיַּיִן תְּחִלָּה וְאַחַר כָּךְ מְקַדֵּשׁ. וְאֵינוֹ נוֹטֵל אֶת יָדָיו עַד שֶׁיְּקַדֵּשׁ:

הבדלה

בראשית רבה י״א:ב׳

כֵּיוָן שֶׁשָּׁקְעָה הַחַמָּה בְּמוֹצָאֵי שַׁבָּת הִתְחִיל הַחשֶׁךְ מְמַשְׁמֵשׁ וּבָא וְנִתְיָרֵא אָדָם הָרִאשׁוֹן, שֶׁנֶּאֱמַר (תהלים קלט, יד): וָאֹמַר אַךְ חשֶׁךְ יְשׁוּפֵנִי וְלַיְלָה אוֹר בַּעֲדֵנִי, אוֹתוֹ שֶׁכָּתוּב בּוֹ (בראשית ג, טו): הוּא יְשׁוּפְךָ רֹאשׁ וְאַתָּה תְּשׁוּפֶנּוּ עָקֵב, בָּא לְהִזְדַּוֵּג לִי, מֶה עָשָׂה הַקָּדוֹשׁ בָּרוּךְ הוּא, זִמֵּן לוֹ שְׁנֵי רְעָפִים וְהֵקִישָׁן זֶה לָזֶה וְיָצָא מֵהֶן אוֹר וּבֵרַךְ עָלֶיהָ, הֲדָא הוּא דִכְתִיב: וְלַיְלָה אוֹר בַּעֲדֵנִי. מַה בֵּרַךְ עָלֶיהָ, בּוֹרֵא מְאוֹרֵי הָאֵשׁ. אַתְיָא כִּשְׁמוּאֵל, דְּאָמַר שְׁמוּאֵל מִפְּנֵי מָה מְבָרְכִין עַל הָאוֹר בְּמוֹצָאֵי שַׁבָּת, מִפְּנֵי שֶׁהִיא תְּחִלַּת בְּרִיָּתָהּ. רַב הוּנָא בְּשֵׁם רַב וְרַבִּי אַבָּהוּ בְּשֵׁם רַבִּי יוֹחָנָן אָמַר, אַף מוֹצָאֵי יוֹם הַכִּפּוּרִים מְבָרְכִין עָלָיו, מִפְּנֵי שֶׁשָּׁבַת הָאוּר כָּל אוֹתוֹ הַיּוֹם.

קידושא רבא

פסחים ק״ו

תָּנוּ רַבָּנַן: ״זָכוֹר אֶת יוֹם הַשַּׁבָּת לְקַדְּשׁוֹ״ — זוֹכְרֵהוּ עַל הַיַּיִן. אֵין לִי אֶלָּא בְּיוֹם, בַּלַּיְלָה מִנַּיִן? תַּלְמוּד לוֹמַר: ״זָכוֹר אֶת יוֹם הַשַּׁבָּת לְקַדְּשׁוֹ״. ״בַּלַּיְלָה מִנַּיִן״?! אַדְּרַבָּה, עִיקַּר קִדּוּשָׁא בַּלַּיְלָה הוּא קָדֵישׁ, דְּכִי קָדֵישׁ — תְּחִלַּת יוֹמָא בָּעֵי לְקַידּוֹשֵׁי! וְתוּ: ״בַּלַּיְלָה מִנַּיִן תַּלְמוּד לוֹמַר: זָכוֹר אֶת יוֹם״, תַּנָּא מְיהַדַּר אַלַּיְלָה וְקָא נָסֵיב לֵיהּ קְרָא דִּימָמָא?! הָכִי קָאָמַר: ״זָכוֹר אֶת יוֹם הַשַּׁבָּת לְקַדְּשׁוֹ״ — זוֹכְרֵהוּ עַל הַיַּיִן בִּכְנִיסָתוֹ, אֵין לִי אֶלָּא בַּלַּיְלָה, בַּיּוֹם מִנַּיִן? תַּלְמוּד לוֹמַר: ״זָכוֹר אֶת יוֹם הַשַּׁבָּת״. בְּיוֹם מַאי מְבָרֵךְ? אָמַר רַב יְהוּדָה: ״בּוֹרֵא פְּרִי הַגֶּפֶן״. רַב אָשֵׁי אִיקְּלַע לְמָחוֹזָא, אֲמַרוּ לֵיהּ: לִיקַדֵּישׁ לַן מָר קִידּוּשָׁא רַבָּה (הַבוּ לֵיהּ). סְבַר: מַאי נִיהוּ ״קִידּוּשָׁא רַבָּה״? אָמַר, מִכְּדֵי כׇּל הַבְּרָכוֹת כּוּלָּן ״בּוֹרֵא פְּרִי הַגֶּפֶן״ אָמְרִי בְּרֵישָׁא, אֲמַר ״בּוֹרֵא פְּרִי הַגֶּפֶן״ וְאַגֵּיד בֵּיהּ. חַזְיֵיהּ לְהָהוּא סָבָא דְּגָחֵין וְשָׁתֵי, קָרֵי אַנַּפְשֵׁיהּ ״הֶחָכָם עֵינָיו בְּרֹאשׁוֹ״.

Pesachim 106

And learn from it that if one has only one cup of wine, he may recite two sanctifications over one cup, as the baraita states that one may recite two entirely unrelated blessings over a single cup. And learn from it that this baraita is according to the ruling of Beit Shammai, in accordance with the explanation of Rabbi Yehuda, who says that Beit Shammai maintain that one should recite the blessing over fire before the blessing over spices. Rav Ashi said: On close examination, two of the inferences from the baraita, the ruling that once one who has tasted the cup has disqualified it and the ruling that a cup of blessing requires a specific minimum measure, are actually one matter and should not be counted separately. Rav Ashi elaborates: And this is what the baraita is saying: What is the reason that once one has tasted the cup he has disqualified it from further usage as a cup of blessing? It is because a cup of blessing requires a specific minimum measure. Once one has tasted, there is not enough wine left in the cup. The disqualification is not because of the act of tasting itself. If enough wine remains in the cup after one has taken a sip, it may be used again as a cup of blessing. This ruling is not in accordance with the opinion of certain Sages, who maintain that sipping from the cup itself constitutes an inherent disqualification. The Gemara relates that Rabbi Ya’akov bar Idi was particular with regard to a blemished pitcher, i.e., he would not recite kiddush or havdala with a pitcher from which someone had already taken a sip. Rav Idi bar Sheisha was particular with regard to a blemished cup. Mar bar Rav Ashi was particular even with regard to a blemished barrel and would take wine for kiddush only from a previously unopened barrel. The Sages taught in a baraita with regard to the verse: “Remember the day of Shabbat to sanctify it” (Exodus 20:7): Remember it over wine, through the recitation of kiddush. I have only derived that there is a mitzva to recite kiddush during the day, as the verse is referring to the day of Shabbat. From where do I derive that one must also recite kiddush at night? The verse states: “Remember the day of Shabbat to sanctify it,” which indicates that one should also remember Shabbat as soon as it is sanctified. The Gemara expresses surprise at this last question: From where is it derived that one must recite kiddush at night? Is this the appropriate question? On the contrary, the essential mitzva of kiddush is to sanctify the day at night, as one must sanctify the beginning of the day, i.e., Friday night; there is no reason to sanctify Shabbat in the middle of the day, i.e., in the morning. And furthermore, the continuation of the baraita states: From where do we derive the obligation of kiddush at night? The verse states: “Remember the day of Shabbat.” The tanna is seeking a source for kiddush at night, and yet he cites a verse that is referring to the day. The Gemara answers that this is what the tanna is saying: “Remember the day of Shabbat to sanctify it” is a mitzva to remember it over wine when it begins. I have only derived the obligation to recite kiddush at night; from where do I derive that one must also recite kiddush during the day? The verse states: “Remember the day of Shabbat.” The emphasis of the word day indicates that one must recite kiddush again during the day. The Gemara asks: During the day, when one does not recite the same kiddush as at night, what blessing does one recite? Rav Yehuda said: Before the meal, one brings a cup of wine and simply recites the usual blessing over wine: Who creates the fruit of the vine. The Gemara relates that Rav Ashi happened to come to the city of Meḥoza. The Sages of Meḥoza said to him on Shabbat day: Will the Master recite for us the great kiddush? And they immediately brought him a cup of wine. Rav Ashi was unsure what they meant by the term great kiddush and wondered if the residents of Meḥoza included other matters in their kiddush. He thought: What is this great kiddush to which they refer? He said to himself: Since with regard to all the blessings that require a cup of wine, one first recites the blessing: Who creates the fruit of the vine, I will start with that blessing. He recited: Who creates the fruit of the vine, and lengthened it to see if they were expecting an additional blessing. He saw a particular elder bending over his cup and drinking, and he realized that this was the end of the great kiddush. He read the following verse about himself: “The wise man, his eyes are in his head” (Ecclesiastes 2:14), as he was alert enough to discern the expectations of the local residents. As stated above, the sons of Rabbi Ḥiyya say: One who did not recite havdala at the conclusion of Shabbat may recite havdala anytime over the course of the entire week. The Gemara asks: And until how many days of that week have passed may one still recite havdala? Rabbi Zeira said: Until the fourth day of the week, Wednesday, after which it is no longer considered the same week as the previous Shabbat. This is like that ruling of halakha stated when Rabbi Zeira sat before Rav Asi, and some say it was Rav Asi who sat before Rabbi Yoḥanan. And he sat and said: With regard to the wording of bills of divorce, the first day of the week and the second and third days of the week are all called: After Shabbat. If a bill of divorce or a condition upon which the document depends includes the phrase: After Shabbat, it refers to one of the first three days of the week. However, the fourth and fifth days of the week and the eve of the day of Shabbat are called: Before Shabbat. Likewise, with regard to havdala, the first three days of the week are considered the time period after Shabbat, and therefore one may still recite havdala on these days. Rabbi Ya’akov bar Idi said: However, one who recites havdala during this time period may not recite the blessing over fire. This blessing may be recited only at the conclusion of Shabbat, at the time when fire was originally created. Rav Beruna said that Rav said: One who washes his hands should not recite kiddush after washing, as this would constitute an interruption between washing and eating, and he will have to wash again. Instead, he should hear kiddush from someone else. Rav Yitzḥak bar Shmuel bar Marta said to them: Not a lot of time has yet passed since Rav died, and we have already forgotten his halakhic rulings. Many times I stood before Rav and saw that sometimes he preferred bread, and he would recite kiddush over bread. On those occasions Rav would wash his hands, recite kiddush over the bread, and eat it. At other times he preferred wine and would recite kiddush over wine. This shows that kiddush is not considered an interruption between washing one’s hands and eating bread. Rav Huna said that Rav said: One who has tasted any food on Shabbat night may not recite kiddush anymore that night, as one must recite kiddush before he eats. Instead, he recites kiddush during the day before the meal. Rav Ḥana bar Ḥinnana raised a dilemma before Rav Huna: If one tasted food at the conclusion of Shabbat before reciting havdala, what is the halakha with regard to whether he may recite havdala? He said to him: I say that one who has tasted food may still recite havdala. And Rav Asi said: One who has tasted food may not recite havdala. The Gemara relates that Rav Yirmeya bar Abba happened to come to the house of Rav Asi. He forgot and tasted some food after Shabbat before havdala. They gave him a cup and he recited havdala. Later, Rav Asi’s wife said to her husband: But my Master does not act this way. In your opinion, one who eats before havdala does not recite havdala. He said to her: Leave Rav Yirmeya bar Abba. He maintains in accordance with the opinion of his rabbi. Rav Yirmeya bar Abba was a student of Rav, who ruled that even one who has eaten may recite havdala. Rav Yosef said that Shmuel said: One who has tasted food before kiddush may not recite kiddush, and one who has tasted food before havdala may not recite havdala. And Rabba said that Rav Naḥman said that Shmuel said: One who has tasted may nevertheless recite kiddush, and one who has tasted may likewise recite havdala.

משנה תורה, הלכות שבת כ״ט:י׳

מִי שֶׁנִּתְכַּוֵּן לְקַדֵּשׁ עַל הַיַּיִן בְּלֵילֵי שַׁבָּת וְשָׁכַח וְנָטַל יָדָיו קֹדֶם שֶׁיְּקַדֵּשׁ הֲרֵי זֶה מְקַדֵּשׁ עַל הַפַּת וְאֵינוֹ מְקַדֵּשׁ עַל הַיַּיִן אַחַר שֶׁנָּטַל יָדָיו לַסְּעֻדָּה. וּמִצְוָה לְבָרֵךְ עַל הַיַּיִן בְּיוֹם הַשַּׁבָּת קֹדֶם שֶׁיִּסְעֹד סְעֻדָּה שְׁנִיָּה. וְזֶה הוּא הַנִּקְרָא קִדּוּשָׁא רַבָּה. מְבָרֵךְ בּוֹרֵא פְּרִי הַגָּפֶן בִּלְבַד וְשׁוֹתֶה וְאַחַר כָּךְ יִטּל יָדָיו וְיִסְעֹד. וְאָסוּר לוֹ לְאָדָם שֶׁיִּטְעֹם כְּלוּם קֹדֶם שֶׁיְּקַדֵּשׁ. וְגַם קִדּוּשׁ זֶה לֹא יִהְיֶה אֶלָּא בִּמְקוֹם סְעֻדָּה:

Mishneh Torah, Sabbath 29:10

A person who had intended to recite kiddush over wine on Friday night, but forgot, and before he recited kiddush washed his hands [with the intention of partaking of bread], should recite kiddush over bread. He should not recite kiddush over wine after washing his hands [to partake of] a meal.
It is a mitzvah to recite a blessing over wine on the Sabbath day before partaking of the second [Sabbath] meal. This is called "the great kiddush." One recites only the blessing borey pri hagefen, partakes of the wine, washes one's hands, and begins the meal.
[On the Sabbath day as well,] a person is forbidden to taste any food before he recites kiddush. This kiddush may also be recited only in the place where one eats one's meal.

השגות הראב"ד על משנה תורה, הלכות שבת כ״ט:י׳:א׳

ואסור לו לאדם וכו'. כתב הראב''ד ז''ל בחיי ראשי אם מסברא אמרה לא סבר מימיו סברא פחותה מזו ולפי שקראוהו קדושא רבא יצא לו, ואינו כלום שכבר נתקדש היום בכניסתו על היין קודם שיטעום ואילו בא לקדש על הפת מי לא מקדש ותחשב המוציא במקום ברכת היין ויאכל וכשדרשו אין לי אלא בלילה ביום מנין ת''ל את יום אסמכתא היא דעיקר קדושא בליליא כתיב מדכתיב את יום ולא כתיב ביום א''נ דאי לא קדיש בליליא קאמר, עכ''ל:

Hasagot HaRa'avad on Mishneh Torah, Sabbath 29:10:1

...