Noam Beit Midrash - Asserting Authority

How does the court test the witnesses? The pair which arrives first, they test them first. They bring in the older of them and they say to him, “Tell us, how did you see the moon in front of the sun or behind the sun? To the north of it or to the south? How high was it, and in which direction was it inclined? And how broad was it?” If he says [he saw it] in front of the sun, his evidence is rejected. After that they would bring in the second and test him. If their accounts were the same, their evidence was accepted. And the other pairs were only questioned briefly, not because they were required at all, but so that they should not go out disappointed, so that they would be regular in coming [to testify].

Rabban Gamliel had, on a tavla, on the walls of his loft, various drawings of the moon, which he showed to uneducated witnesses, and said, "Was it like this one that you saw, or like this one?”

It happened once, that two witnesses came and said, "We saw [the moon] in the East in the morning, and in the evening in the West." Rabbi Yochanan ben Nuri said, "They are false witnesses." But when they came to Yavneh, Rabban Gamliel accepted them.

And another time, two witnesses came and said, "We saw the moon at its time [meaning, on the first of the two possible days], but it was not to be seen on the [next] evening of its fullness," and Rabban Gamliel accepted them.

Rabbi Dosa ben Harkinus said, "They are false witnesses; how can they testify that a woman gave birth, and, on the next day that her 'womb was between her teeth’?!”

Rabbi Yehoshua said to him, "I see what you’re saying.”

9] Rabban Gamliel sent [Rabbi Yehoshua] a message, saying, "I decree upon you to come to me with your staff and your wallet on the day that comes out to be Yom Kippur, according to your calculation.”

Rabbi Akiva went to [Rabbi Yehoshua], and found him grieving; he said to him, "I have a teaching that all that Rabban Gamliel has done is to be done, as it is stated (Leviticus 23:4), 'These are the feasts of God, holy convocations which you shall proclaim;' whether at their time, or whether not at their time, I have no holy convocations other than those.”

When he came to Rabbi Dosa ben Harkinus, [the latter] said to him, "If we make judgements after the court of Rabban Gamliel, we must also make judgements after all the courts which have stood, from the days of Moses until now; as it is stated: (Exodus 24:2), 'Moshe, Aharon, Nadav, Avihu, and seventy of the elders of Israel went up.' Why were the names of the elders not specified? To teach, that every three people that form a court over Israel, is like the court of Moses.”

Rabbi Yehoshua took his staff and his wallet in his hand, and went to Yavneh to Rabban Gamliel on the day that came out to be Yom Kippur, according to his calculation. Rabban Gamliel stood up, and kissed him on his head. He said to him, "Come in peace, my teacher and my student! My teacher — in wisdom; and my student — in that you accepted my words."