Rosh Hashana 2:9-3:1

Rosh Hashana 2:9

(Continuing the story begun in 2:8, in which Rabbi Yehoshua disagreed with Rabban Gamliel regarding when to declare the new month.) Rabban Gamliel sent word to Rabbi Yehoshua, ordering him to appear before him with his staff and money in hand on the day that would be Yom Kippur according to Rabbi Yehoshua’s calculations. Rabbi Akiva found Rabbi Yehoshua was very upset so he told him to follow Rabban Gamliel’s instructions. The Torah teaches (Leviticus 23:4), “These are the holidays of Hashem, holy convocations that you shall proclaim.” The holidays are proclaimed whether they are at their designated time or not; the only criterion is that they are proclaimed by the court. When Rabbi Yehoshua spoke to Rabbi Dosa ben Harkinus (with whose opinion he had agreed against Rabban Gamliel), Rabbi Dosa said, "If we question the accuracy of Rabban Gamliel’s opinion, we must also question the accuracy of every court ever, from the time of Moshe until today.” The Torah says (Exodus 24:2), “Moshe, Aharon, Nadav, Avihu and 70 elders of Israel went up.” Why aren’t the names of the elders specified? It is to teach that every three men who form ‏a court are equivalent to the court formed by Moshe.” Rabbi Yehoshua took his staff and his money in hand, and went to see Rabban Gamliel in Yavne on the day that he calculated to be Yom Kippur. When he arrived, Rabban Gamliel arose, kissed him on his head and said, “Come in peace, my teacher and my student! You are my teacher in wisdom and my student in that you accepted my words!”

Rosh Hashana 3:1

Even if the court and all of Israel saw the new moon, if there was no time to declare the new month after examining the witnesses before it gets dark, then the month will be intercalated (i.e., a day longer). If only the court saw it, two of them must stand and testify before the others, who will reply, “Consecrated, consecrated.” If a court of only three members saw it, two of them stand, they seat two of their colleagues with the third person, and they testify before them, the others responding, “Consecrated, consecrated.” This is because one person (that third member of the original three) cannot perform this function by himself.