Commentary for Rosh Hashanah 2:8
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:
R. Gamliel had figures of the different forms of the moon, [depicting the size of the moon and the direction of the inclination of its rays], which he would show to those unversed (in technical terminology, who came to testify to the appearance of the new moon), asking them: "Did it look like this or like this?" Once, two witnesses came and said: "We saw it in the morning in the east, and in the evening in the west." R. Yochanan b. Nuri said: They are false witnesses. And when they came to Yavneh, R. Gamliel accepted their testimony. [Not because he thought that it was possible to see the moon in the morning in the east at the beginning of sunrise, and, in the same day, to see it in the west at sunset. For this is impossible. Rather, he accepted their testimony as to having seen the moon in the west in the evening, knowing, by calculation, that this was a possibility for that night. As to their saying that they had seen it in the morning in the east, he assumed that they had been deceived by having seen clouds in the form of the moon in the firmament. As it is taught in the baraitha (25a): "Once the skies were clouded over and the form of the moon appeared on the twenty-ninth of the month, etc." And R. Yochanan b. Nuri, who called them "false witnesses" — According to his calculation it was impossible for the witnesses to have seen the moon that night, there not having been enough time between their sighting and the molad ("birth" of the moon) for them to have seen it. And on this account R. Gamliel counters in the baraitha: "Thus have I received it from my father's father's house: Sometimes it comes longer; sometimes it comes shorter." That is, the time between the molad and the appearance of the moon is not always the same. For sometimes the movement of the moon is faster, and, sometimes, slower. And by the speed of the moon's movement at that time, R. Gamliel calculated that the moon could have been seen on that night, for which reason he accepted their testimony.] On another occasion, two witnesses came and testified: "We saw it in its (regular) time [the night of the thirtieth], but it was not visible on the night of its fullness" [the night of the thirty-first], and R. Gamliel accepted their testimony. [Not because he assumed that the moon moved away from the sun on the night of the thirtieth, so as to be visible, and then turned back towards the sun on the night of the thirty-first, so that it was concealed. For the moon does not turn back, but moves continuously in its orbit. Rather, R. Gamliel knew by calculation that on that night when the witnesses claimed to have seen it, the moon had already moved far enough from the sun to be visible, for which reason he accepted their testimony. As to their saying: "but it was not visible on the night of its fullness," it is possible that it had been covered by the clouds or that they could not see it because of some other reason.] R. Dossa b. Hyrcanus said: "They are false witnesses. It is like testifying about a woman that she has given birth, and the next morning finding her belly between her teeth!" R. Yehoshua said: "I accept your words" [to intercalate the month].
Bartenura on Mishnah Rosh Hashanah
English Explanation of Mishnah Rosh Hashanah
It happened that two witnesses came and said, “We saw it in the morning in the east and in the evening in the west.” Rabbi Yohanan ben Nuri said: they are lying witnesses. When they came to Yavneh Rabban Gamaliel accepted them.
On another occasion two witnesses came and said, “We saw it at its proper time, but on the night which should have been the new moon it was not seen,” and Rabban Gamaliel accepted their evidence. Rabbi Dosa ben Harkinas said: they are lying witnesses. How can they testify that a woman has given birth when on the next day her belly is between her teeth (? Rabbi Joshua to him: I see your argument.
This mishnah and the next one contain one of the most famous stories in rabbinic literature. In it Rabban Gamaliel and Rabbi Joshua clash over accepting what seems to surely be false testimony as to the new moon.
Section one: This section sets up the character of Rabban Gamaliel, who will play the lead role in the story. Rabban Gamaliel was the head of the court in Yavneh and he was the rabbi who would ultimately decide whether the witnesses’ testimony would be accepted and the new month sanctified. In order to facilitate this, he would have pictures of the moon in its different phases hung up in his upper chamber, where he would interrogate them.
Section two: The story now begins. Two witnesses come in front of some rabbi (it’s not clear whom they come in front of) and tell him that they saw the new moon in the morning in the east and in the evening in the west. This is impossible and hence Rabbi Dosa ben Harkinas calls them lying witnesses. The witnesses proceed on to Yavneh and come in front of Rabban Gamaliel, who sanctifies the month based on their testimony. We as readers of the mishnah are properly shocked wasn’t Rabban Gamaliel the very rabbi who was especially fervent in checking the witnesses?
The same thing seems to happen a second time. Again witnesses offer impossible testimony, which Rabbi Dosa ben Harkinas promptly rejects, this time using a graphic analogy. In Hebrew there is a pun which is lost in translation. The word for pregnant and the word for a thirty day month are the same.
In the final line of the mishnah, a new character is added, Rabbi Joshua. Rabbi Joshua agrees with Rabbi Dosa ben Harkinas, setting the stage for his eventual clash with Rabban Gamaliel in tomorrow’s mishnah.