Mishnah Rosh Hashanah

8. It happened that two witnesses came and said, “We saw it [the new moon] in the morning in the east and in the evening in the west.” R. Yoḥanan 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. R. 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 [i.e., distended]? R. Joshua to him: I see your argument.

9. Rabban Gamaliel sent to him [R. Joshua]: I order you to appear before me with your staff and your money on the day that according to your count should be Yom Kippur. R. Akiva went and found him in distress. He [R. Akiva] said to him [R. Joshua]: I can teach that whatever Rabban Gamaliel has done is valid, because it says: These are the appointed seasons of the Lord, holy convocations, which you shall proclaim at their appointed times (Leviticus 23:4), whether they are [proclaimed] at their proper time or not at their proper time, I have no other appointed times except these. He [R. Joshua] then went to R. Dosa ben Harkinas. He [R. Dosa ben Harkinas] said to him: if we call into question the court of Rabban Gamaliel, we must call into question the decisions of every court that has existed since the days of Moses until now. [ . . . ]

[Then] he [R. Joshua] took his staff and his money and went to Yavneh to Rabban Gamaliel on the day on which Yom Kippur fell according to his count. Rabban Gamaliel rose and kissed him on his head and said to him: Come in peace, my teacher and my student, my teacher in wisdom and my student because you have accepted my decision.

Adapted from the translation ofJoshua Kulp.