(Mishnah): The Great Sanhedrin consisted of 71 judges and the small one consisted of 23 judges.

What is the source for the Great Sanhedrin consisting of 71 judges? The pasuk states (Bamidbar 11:16), "Gather for me 70 men from the elders of Yisrael" with Moshe as the head (as learned from the next pasuk 'and they will bear with you the burden of the nation')- that makes 71.

(R. Yehuda): There are only 70 (as that pasuk 'and they will bear with you...' merely teaches that the elders must be similar to Moshe in their lineage and their traits).

Question: What is the source for the small Sanhedrin consisting of 23 judges? The pasuk states (Bamidbar 35:24-25), "And they shall judge the congregation...and they will save the congregation" - a congregation (10 judges) will judge and a congregation (10 judges) will save - that makes 20 judges.

What is the source that the word 'Eidah' - 'congregation' means 10 people? As the pasuk states (Bamidbar 14:27), "how long will there be this evil congregation" - in reference to the spies who came back from the Land of Israel with a bad report. There were 12 spies, but two of them did not sin - Yehoshua and Calev. The pasuk is addressing the rest of them, meaning 10 people.

Question: What is the source for the other three judges required? From the pasuk (Shemos 23:2), "You should not follow after the majority to do evil" - I learn that I should not follow the majority to evil, but to do good, I should follow the majority.

If so, why did the pasuk also need to end by saying 'to follow after the majority'? The way you follow the bad should not be as you follow the good. Following the majority for the good can be done with a majority of only one; for the bad, two are required. Therefore, two extra judges are required in addition to the first twenty in order that there will potentially be 12 against 10 to save an innocent man. However, Beis Din must always comprise of an odd number, so there must be 23 judges.

Question: How many people must live in a city for it to have a small Sanhedrin?

Answer: (At least) 120 people.

Answer #2 (R. Nechemiah): (At least) 230 people, so that each judge (of the 23) should preside over ten people of the city.

(Gemara)(R. Ba/ R. Yasa citing R. Yochanan): (The following Gezeirah Shavah is used to expound that ten men are needed in order to perform any public holy matter, such as reciting Kaddish, Kedushah, and Barchu etc.) - the word 'Eidah' (congregation) is used here (Vayikra 19:2, "speak to all of the congregation of the children of Israel and say to them, you shall be holy") and the word 'Eidah' is used there (Bamidbar 14:27, about the spies, "how long will there be this evil congregation". Just as there were ten evil spies, so too matters of holiness require ten people.

Source #2: (R. Simon): The word 'Toch' (the midst) is used here (Vayikra 22:32, "I will be sanctified in the midst of the children of Israel") and the word 'Toch' is used there (Bereishis 42:5, "and the children of Israel came to buy amidst those who came"). Just as there were ten sons of Yaakov who came, as Yosef was already in Egypt and Binyamin did not come, so too "I will be sanctified in the midst" requires ten.

Rebuttal (R. Yosa bei R. Bun): If you are learning from "amidst those who came", there were many people that came?

Alternative answer: Rather, the words 'Bnei Yisrael' (the children of Israel) are used here (Vayikra 22:32, "I will be sanctified in the midst of the children of Israel") and the words 'Bnei Yisrael' are used there (Bereishis 42:5, "and the children of Israel came to buy amidst those who came"). Just as there were ten sons of Yaakov who came, so too "I will be sanctified..." requires ten.

The Mishnah taught: (See above 17-1 (d) 2.) What is the source for the other three judges required?

Beraisa (Rabban Shimon ben Gamliel): Originally, only Kohanim, Leviim and Yisraelim who they themselves were permitted to marry women proven to be of good lineage, would sign as witnesses on the marriage documents (Kesuvos) of such women.

(R. Yosi): Originally, dispute would never endure amongst the Jews, as the Sanhedrin of 71 sat in the Lishchas HaGazis (The Chamber of Hewn Stone) and resolved all disputes.

And there were two Beis Dins of 23 judges that would sit, one in the Chayil and one on the Temple Mount.

And Beis Dins of 23 would sit in all of the cities of the Land of Israel.

If a person needed to ask a question of Jewish Law, he would ask the Beis Din of 23 judges in his city. If they had heard the answer from their Rabbis, they would tell him the ruling; if not, the questioner and the greatest judge of that Beis Din would go and ask in the next closest Beis Din.

If that Beis Din had heard the answer, they would tell him; if not, the questioner and the greatest judge of that Beis Din would go and ask the Beis Din on the Temple Mount.

If that Beis Din had heard the answer, they would tell him; if not, the questioner and the greatest judge of that Beis Din would go and ask the Beis Din in the Chayil (at the entrance of the courtyard).

If that Beis Din had heard the answer, they would tell him; if not, the questioner and the Beis Din of the Chayil would go and ask the Beis Din HaGadol in the Lishchas HaGazis, from which Torah came forth to all of Yisrael, as the pasuk states (Devarim 17:10), "from the place that Hash-m chose..."

The Sanhedrin in the Lishchas HaGazis - even though there were (potentially as many as) 71 judges, there could never be a hearing with less than 23 of them.

If one of the judges needed to leave, he would first need to check that there were at least 23 without him. They would sit in court from the early morning, from the time that the Kohanim sacrificed the first daily Tamid offering until the time of the second Tamid offering in the late afternoon.

On Shabbos and Yom Tov, they would sit in the Study Hall on the Temple Mount (so that it would not look as if they were judging monetary and capital cases).

If they were asked a question, if they had heard an answer, they say it; otherwise they counted up the judges - if the majority found him to be exempt, he is exempt; liable to pay, he is liable to pay. If the majority found him guilty (of a capital offense), he is guilty; if they found him innocent, he is innocent. If the majority found him to be pure, he is pure; impure, he is impure. It is through this that the Torah is made known amongst all of Yisrael.

When the number of students of Shammai and Hillel who had not sufficiently served their teachers and fully understood the meaning behind the laws, dispute increased amongst Yisrael and the two groups became as two Torahs.

From there (the Great Sanhedrin) would send messages throughout the Land of Israel and whoever that was found to be wise, not searching for honor, calm, content, non-materialistic, humble, well balanced, of good inclination and successful, they would seat him in the Beis Din that was on the Temple Mount and then in the Beis Din in the Chayil and then in the Beis Din HaGadol in the Lishchas HaGazis.