(א) וַיֹּ֤אמֶר יְהֹוָה֙ אֶל־מֹשֶׁ֣ה וְאֶֽל־אַהֲרֹ֔ן בְּאֶ֥רֶץ מִצְרַ֖יִם לֵאמֹֽר׃ (ב) הַחֹ֧דֶשׁ הַזֶּ֛ה לָכֶ֖ם רֹ֣אשׁ חֳדָשִׁ֑ים רִאשׁ֥וֹן הוּא֙ לָכֶ֔ם לְחׇדְשֵׁ֖י הַשָּׁנָֽה׃
(1) יהוה said to Moses and Aaron in the land of Egypt: (2) This month shall mark for you the beginning of the months; it shall be the first of the months of the year for you.
(א) חָדְשֵׁי הַשָּׁנָה הֵם חָדְשֵׁי הַלְּבָנָה שֶׁנֶּאֱמַר (במדבר כח יד) "עלַת חֹדֶשׁ בְּחָדְשׁוֹ" וְנֶאֱמַר (שמות יב ב) "הַחֹדֶשׁ הַזֶּה לָכֶם רֹאשׁ חֳדָשִׁים". כָּךְ אָמְרוּ חֲכָמִים הֶרְאָה לוֹ הַקָּדוֹשׁ בָּרוּךְ הוּא לְמשֶׁה בְּמַרְאֵה הַנְּבוּאָה דְּמוּת לְבָנָה וְאָמַר לוֹ כָּזֶה רְאֵה וְקַדֵּשׁ. וְהַשָּׁנִים שֶׁאָנוּ מְחַשְּׁבִין הֵם שְׁנֵי הַחַמָּה שֶׁנֶּאֱמַר (דברים טז א) "שָׁמוֹר אֶת חֹדֶשׁ הָאָבִיב":
(1) The months of the year are lunar months, as [implied by Numbers 28:14]: "... the burnt offering of the month when it is renewed,"1The concept of a renewal each month is relevant regarding lunar months, but not with regard to solar months. For the moon is not seen for a day or two each month, while the sun shines continually every day throughout the year. and [Exodus 12:2]: "This month shall be for you the first of months."2Although the implication to a lunar month in this verse is not as obvious as in the former verse, there is an explicit teaching from our Sages indicating a connection, as the Rambam proceeds to explain. [Concerning this verse,] our Sages commented:3Mechilta D'Rashbi on the above verse; see also Midrash Tanchumah, Shemini, sec. 8; Menachot 29a. The Holy One, blessed be He, showed Moses in the vision of prophecy an image of the moon and told him, "When you see the moon like this, sanctify it."The years we follow are solar years, as [implied by Deuteronomy 16:1]: "Keep the month of spring."4Sanhedrin 13b (cited by the Rambam, Chapter 4, Halachah 1) explains that this verse is a charge to arrange the calendar so that the vernal (spring) equinox always falls in the month of Nisan.
וַאֲנָא אָמֵינָא טַעְמָא דִידִי וְטַעְמָא דִידְכוּ. טַעְמָא דִידְכוּ: שַׁבָּת, דִּקְבִיעָא וְקַיְימָא — בֵּין בִּצְלוֹתָא וּבֵין בְּקִידּוּשָׁא: ״מְקַדֵּשׁ הַשַּׁבָּת״. יוֹמָא טָבָא, דְּיִשְׂרָאֵל הוּא דְּקָבְעִי לֵיהּ — דְּקָמְעַבְּרִי יַרְחֵי וְקָבְעִי לְשָׁנֵי: ״מְקַדֵּשׁ יִשְׂרָאֵל וְהַזְּמַנִּים״.
Rava further said to the Elders of Pumbedita: And I can say my reason and your reason. Your reason is that since Shabbat is established and permanent, i.e., it always occurs on the seventh day of the week, both in prayers and in kiddush one should recite: Who sanctifies Shabbat. It is not necessary for Israel to sanctify Shabbat, as it is permanently sanctified by God. Conversely, with regard to a Festival, as it is Israel who establishes it, as the Sages add extra days to certain months and establish years by intercalating them, one recites: Who sanctifies Israel and the seasons. This is Rava’s explanation of the reason for the ruling of the Elders of Pumbedita.
(א) אִם אֵינָן מַכִּירִין אוֹתוֹ, מְשַׁלְּחִין אַחֵר עִמּוֹ לַהֲעִידוֹ. בָּרִאשׁוֹנָה הָיוּ מְקַבְּלִין עֵדוּת הַחֹדֶשׁ מִכָּל אָדָם. מִשֶּׁקִּלְקְלוּ הַמִּינִין, הִתְקִינוּ שֶׁלֹּא יְהוּ מְקַבְּלִין אֶלָּא מִן הַמַּכִּירִים:
(ב) בָּרִאשׁוֹנָה הָיוּ מַשִּׂיאִין מַשּׂוּאוֹת. מִשֶּׁקִּלְקְלוּ הַכּוּתִים, הִתְקִינוּ שֶׁיְּהוּ שְׁלוּחִין יוֹצְאִין:
(1) If the members of the Great Sanhedrin in Jerusalem are not familiar with that one who saw the new moon, i.e., that he is a valid witness, the members of his local court of twenty-three send another with him to testify about him. The mishna adds: Initially, the court would accept testimony to determine the start of the month from any person, as all are presumed to be qualified witnesses, absent any disqualifying factors. However, when the Boethusians, a sect whose members had their own opinions with regard to the establishment of the Festivals, corrupted the process by sending false witnesses to testify about the new moon, the Sages instituted that they would accept this testimony only from those men familiar to the Sanhedrin as valid witnesses.
(2) Initially, after the court sanctified the new month they would light torches on the mountaintops, from one peak to another, to signal to the community in Babylonia that the month had been sanctified. After the Samaritans [Kutim] corrupted and ruined this method by lighting torches at the wrong times to confuse the Jews, the Sages instituted that messengers should go out to the Diaspora and inform them of the start of the month.
(ח) דְּמוּת צוּרוֹת לְבָנוֹת הָיוּ לוֹ לְרַבָּן גַּמְלִיאֵל בַּטַּבְלָא וּבַכֹּתֶל בַּעֲלִיָּתוֹ, שֶׁבָּהֶן מַרְאֶה אֶת הַהֶדְיוֹטוֹת וְאוֹמֵר, הֲכָזֶה רָאִיתָ אוֹ כָזֶה. מַעֲשֶׂה שֶׁבָּאוּ שְׁנַיִם וְאָמְרוּ, רְאִינוּהוּ שַׁחֲרִית בַּמִּזְרָח וְעַרְבִית בַּמַּעֲרָב. אָמַר רַבִּי יוֹחָנָן בֶּן נוּרִי, עֵדֵי שֶׁקֶר הֵם. כְּשֶׁבָּאוּ לְיַבְנֶה קִבְּלָן רַבָּן גַּמְלִיאֵל. וְעוֹד בָּאוּ שְׁנַיִם וְאָמְרוּ, רְאִינוּהוּ בִזְמַנּוֹ, וּבְלֵיל עִבּוּרוֹ לֹא נִרְאָה, וְקִבְּלָן רַבָּן גַּמְלִיאֵל. אָמַר רַבִּי דוֹסָא בֶּן הַרְכִּינָס, עֵדֵי שֶׁקֶר הֵן, הֵיאָךְ מְעִידִין עַל הָאִשָּׁה שֶׁיָּלְדָה, וּלְמָחָר כְּרֵסָהּ בֵּין שִׁנֶּיהָ. אָמַר לוֹ רַבִּי יְהוֹשֻׁעַ, רוֹאֶה אֲנִי אֶת דְּבָרֶיךָ:
(ט) שָׁלַח לוֹ רַבָּן גַּמְלִיאֵל, גּוֹזְרַנִי עָלֶיךָ שֶׁתָּבֹא אֶצְלִי בְּמַקֶּלְךָ וּבִמְעוֹתֶיךָ בְּיוֹם הַכִּפּוּרִים שֶׁחָל לִהְיוֹת בְּחֶשְׁבּוֹנְךָ. הָלַךְ וּמְצָאוֹ רַבִּי עֲקִיבָא מֵצֵר, אָמַר לוֹ, יֶשׁ לִי לִלְמוֹד שֶׁכָּל מַה שֶּׁעָשָׂה רַבָּן גַּמְלִיאֵל עָשׂוּי, שֶׁנֶּאֱמַר (ויקרא כג), אֵלֶּה מוֹעֲדֵי יְיָ מִקְרָאֵי קֹדֶשׁ, אֲשֶׁר תִּקְרְאוּ אֹתָם, בֵּין בִּזְמַנָּן בֵּין שֶׁלֹּא בִזְמַנָּן, אֵין לִי מוֹעֲדוֹת אֶלָּא אֵלּוּ. בָּא לוֹ אֵצֶל רַבִּי דוֹסָא בֶּן הַרְכִּינָס, אָמַר לוֹ, אִם בָּאִין אָנוּ לָדוּן אַחַר בֵּית דִּינוֹ שֶׁל רַבָּן גַּמְלִיאֵל, צְרִיכִין אָנוּ לָדוּן אַחַר כָּל בֵּית דִּין וּבֵית דִּין שֶׁעָמַד מִימוֹת משֶׁה וְעַד עַכְשָׁיו, שֶׁנֶּאֱמַר (שמות כד), וַיַּעַל משֶׁה וְאַהֲרֹן נָדָב וַאֲבִיהוּא וְשִׁבְעִים מִזִּקְנֵי יִשְׂרָאֵל. וְלָמָּה לֹא נִתְפָּרְשׁוּ שְׁמוֹתָן שֶׁל זְקֵנִים, אֶלָּא לְלַמֵּד, שֶׁכָּל שְׁלשָׁה וּשְׁלשָׁה שֶׁעָמְדוּ בֵית דִּין עַל יִשְׂרָאֵל, הֲרֵי הוּא כְבֵית דִּינוֹ שֶׁל משֶׁה. נָטַל מַקְלוֹ וּמְעוֹתָיו בְּיָדוֹ, וְהָלַךְ לְיַבְנֶה אֵצֶל רַבָּן גַּמְלִיאֵל בְּיוֹם שֶׁחָל יוֹם הַכִּפּוּרִים לִהְיוֹת בְּחֶשְׁבּוֹנוֹ. עָמַד רַבָּן גַּמְלִיאֵל וּנְשָׁקוֹ עַל רֹאשׁוֹ, אָמַר לוֹ, בֹּא בְשָׁלוֹם, רַבִּי וְתַלְמִידִי, רַבִּי בְחָכְמָה, וְתַלְמִידִי שֶׁקִּבַּלְתָּ דְּבָרָי:
(8) Rabban Gamliel had a diagram of the different forms of the moon drawn on a tablet that hung on the wall of his attic, which he would show to the laymen who came to testify about the new moon but were unable to describe adequately what they had seen. And he would say to them: Did you see a form like this or like this? There was an incident in which two witnesses came to testify about the new moon, and they said: We saw the waning moon in the morning in the east, and that same day we saw the new moon in the evening in the west. Rabbi Yoḥanan ben Nuri said: They are false witnesses, as it is impossible to see the new moon so soon after the last sighting of the waning moon. However, when they arrived in Yavne, Rabban Gamliel accepted them as witnesses without concern. And there was another incident in which two witnesses came and said: We saw the new moon at its anticipated time, i.e., on the night of the thirtieth day of the previous month; however, on the following night, i.e., the start of the thirty-first, which is often the determinant of a full, thirty-day month, it was not seen. And nevertheless Rabban Gamliel accepted their testimony and established the New Moon on the thirtieth day. Rabbi Dosa ben Horkinas disagreed and said: They are false witnesses; how can witnesses testify that a woman gave birth and the next day her belly is between her teeth, i.e., she is obviously still pregnant? If the new moon was already visible at its anticipated time, how could it not be seen a day later? Rabbi Yehoshua said to him: I see the logic of your statement; the New Moon must be established a day later.
(9) Upon hearing that Rabbi Yehoshua had challenged his ruling, Rabban Gamliel sent a message to him: I decree against you that you must appear before me with your staff and with your money on the day on which Yom Kippur occurs according to your calculation; according to my calculation, that day is the eleventh of Tishrei, the day after Yom Kippur. Rabbi Akiva went and found Rabbi Yehoshua distressed that the head of the Great Sanhedrin was forcing him to desecrate the day that he maintained was Yom Kippur. In an attempt to console him, Rabbi Akiva said to Rabbi Yehoshua: I can learn from a verse that everything that Rabban Gamliel did in sanctifying the month is done, i.e., it is valid. As it is stated: “These are the appointed seasons of the Lord, sacred convocations, which you shall proclaim in their season” (Leviticus 23:4). This verse indicates that whether you have proclaimed them at their proper time or whether you have declared them not at their proper time, I have only these Festivals as established by the representatives of the Jewish people. Rabbi Yehoshua then came to Rabbi Dosa ben Horkinas, who said to him: If we come to debate and question the rulings of the court of Rabban Gamliel, we must debate and question the rulings of every court that has stood from the days of Moses until now. As it is stated: “Then Moses went up, and Aaron, Nadav and Avihu, and seventy of the Elders of Israel” (Exodus 24:9). But why were the names of these seventy Elders not specified? Rather, this comes to teach that every set of three judges that stands as a court over the Jewish people has the same status as the court of Moses. Since it is not revealed who sat on that court, apparently it is enough that they were official judges in a Jewish court. When Rabbi Yehoshua heard that even Rabbi Dosa ben Horkinas maintained that they must submit to Rabban Gamliel’s decision, he took his staff and his money in his hand, and went to Yavne to Rabban Gamliel on the day on which Yom Kippur occurred according to his own calculation. Upon seeing him, Rabban Gamliel stood up and kissed him on his head. He said to him: Come in peace, my teacher and my student. You are my teacher in wisdom, as Rabbi Yehoshua was wiser than anyone else in his generation, and you are my student, as you accepted my statement, despite your disagreement.
(ג) וּמֵאֵימָתַי הִתְחִילוּ כָּל יִשְׂרָאֵל לְחַשֵּׁב בְּחֶשְׁבּוֹן זֶה. מִסּוֹף חַכְמֵי הַגְּמָרָא בְּעֵת שֶׁחָרְבָה אֶרֶץ יִשְׂרָאֵל וְלֹא נִשְׁאַר שָׁם בֵּית דִּין קָבוּעַ. אֲבָל בִּימֵי חַכְמֵי מִשְׁנָה וְכֵן בִּימֵי חַכְמֵי הַגְּמָרָא עַד יְמֵי אַבַּיֵּי וְרָבָא עַל קְבִיעַת אֶרֶץ יִשְׂרָאֵל הָיוּ סוֹמְכִין:
(3) When did the entire Jewish people begin using this calendar? At the conclusion of the Talmudic period, when Eretz Yisrael was in ruin, and an established court no longer remained there. In the era of the Sages of the Mishnah, and in the era of the Sages of the Gemara until the time of Abbaye and Ravvah, [the people] would rely on the establishment [of the calendar] in Eretz Yisrael.
אָמַר שְׁמוּאֵל: יָכֵילְנָא לְתַקּוֹנֵי לְכוּלַּהּ גּוֹלָה.
§ Shmuel said: I am able to fix the calendar for the entire Diaspora without witnesses. Shmuel was an expert on the movement of the celestial bodies and on the principles governing leap years and additional days added to months.
(ו) בֵּית דִּין מְחַשְּׁבִין בְּחֶשְׁבּוֹנוֹת כְּדֶרֶךְ שֶׁמְּחַשְּׁבִים הָאִיצְטַגְנִינִים שֶׁיּוֹדְעִין מְקוֹמוֹת הַכּוֹכָבִים וּמַהֲלָכָם וְחוֹקְרִים וּמְדַקְדְּקִים עַד שֶׁיֵּדְעוּ אִם אֶפְשָׁר שֶׁיֵּרָאֶה הַיָּרֵחַ בִּזְמַנּוֹ שֶׁהוּא לֵיל שְׁלֹשִׁים אוֹ אִי אֶפְשָׁר. אִם יָדְעוּ שֶׁאֶפְשָׁר שֶׁיֵּרָאֶה יוֹשְׁבִין וּמְצַפִּין לָעֵדִים כָּל הַיּוֹם כֻּלּוֹ שֶׁהוּא יוֹם שְׁלֹשִׁים. אִם בָּאוּ עֵדִים וּדְרָשׁוּם וַחֲקָרוּם כַּהֲלָכָה וְנֶאֶמְנוּ דִּבְרֵיהֶם מְקַדְּשִׁין אוֹתוֹ. וְאִם לֹא נִרְאָה וְלֹא בָּאוּ עֵדִים מַשְׁלִימִין שְׁלֹשִׁים וְיִהְיֶה חֹדֶשׁ מְעֵבָּר. וְאִם יָדְעוּ בְּחֶשְׁבּוֹן שֶׁאִי אֶפְשָׁר שֶׁיֵּרָאֶה אֵין יוֹשְׁבִים יוֹם שְׁלֹשִׁים וְאֵין מְצַפִּין לָעֵדִים. וְאִם בָּאוּ עֵדִים יוֹדְעִין בְּוַדַּאי שֶׁהֵן עֵדֵי שֶׁקֶר אוֹ שֶׁנִּרְאֵית לָהֶם דְּמוּת לְבָנָה מִן הֶעָבִים וְאֵינָהּ הַלְּבָנָה הַוַּדָּאִית:
(6) The [High] Court would make calculations in a manner resembling11Rav Kapach explains that the Rambam chose his wording exactly. The calculations of the High Court merely "resembled the calculations of the astronomers." In truth, however, they operated under a different system. As the Rambam explains in Chapter 17, Halachah 24, the prophets and the descendants of the tribe of Issachar had a method of calculating the movement of the sun, the moon, and the stars, which had been transmitted to Moses on Mount Sinai. Although this method resembled the method of calculations employed by gentile scholars, it was unique and different. (See also the Rambam's Commentary on the Mishnah, Rosh HaShanah 2:8.)This method of calculation was lost to our people shortly after the composition of the Mishnah. Subsequent texts, including the Rambam's own system of calculation, as explained from Chapter 11 onward, were based on Greek sources. the calculations of the astronomers, who know the location of the stars and their paths [in their orbits]. They would perform careful research to determine whether or not they would be able to sight the moon at the appropriate time - i.e., the thirtieth night.If [the judges] determined that it was possible to sight [the moon], they would sit waiting for witnesses [to come and testify] throughout the entire thirtieth day. If witnesses came, and [the court] examined their testimony according to law, and verified the truth [of their statements], the court would sanctify [the new month]. If [the moon] was not sighted, and witnesses did not come,12Because the moon was covered with clouds or for other similar reasons. (See Chapter 18, Halachah 1.) they would complete the thirtieth day, thus making the month full.If, according to their calculations, [the judges] knew that it was impossible for the moon to be sighted, they would not sit [in session] on the thirtieth day, nor would they await [the arrival] of witnesses. If witnesses came, they would know that they are false witnesses, or that clouds appeared to them in a form resembling the moon, but it was not the real moon.