The next two Mishnayot will talk about the seating arrangement of the great Sanhedrin (court) of 71 great judges and the lower Sanhedrin of 23 judges. The Mishnah says the Sanhedrin, the court, was seated in a shape like half of a round threshing floor. This means they would sit in rows, and those rows would form a semicircle. The purpose of the semicircle, as opposed to a straight line, was to allow the judges to see each other, as well as the people on trial and the witnesses standing before them. If it were a straight line, the judges at one end would not be able to see the judges at the other end. With a semicircle, everybody could see each other. If it were a full circle, they would not be able to see the people in front of them, like the people on trial and the witnesses. The people on trial and the witnesses would not face the judges. Therefore, a semicircle is the right shape for seating the judges.
They would also have two scribes of the judges standing before them. One would be on the right side of the semicircle, and the other on the left. They would write down the opinions of the different judges: who voted to acquit the person, meaning to say that he was innocent, and who said to convict him, meaning that he was guilty. One scribe would write the acquittals—the fact that the guy was innocent. The other would write the reasons for the conviction, that the person was guilty. They would split the duties. Nowadays, this is like a court stenographer: somebody would sit there with a keyboard and write everything out. Here, they would be scribes, and they would write all the details of the trial. So there were two soferim (scribes).
Rabbi Yehuda says, Rabbi Yehuda, no. There weren't two scribes. Rather, there were three scribes. One would write the opinions of the judges who argued that the person on trial was innocent. The other would write the opinions of the judges who said that the person on trial was guilty. The third scribe would write the opinions of everybody: of who was on who, who argued to acquit the person and say he was innocent, and who argued that he was guilty. So that now, if we ever needed them, we would have two witnesses. Two of these three scribes could give testimony about each argument, and they would have their evidence, their proof, in front of them. The whole point of this was that if one of the judges forgot what he held—his logic—the scribe would be able to remind him.