How Is the Composition of  a Court Determined? 

כיצד נקבע הרכב בית המשפט?

Having drawn a conclusion regarding the meaning of the text of the mishna, the Gemara seeks to ascertain the reason for the halakha: What is different about this procedure, i.e., that the selection of the judges is performed specifically in this manner, with each side choosing a judge?

The Gemara answers by citing a halakhic tradition from the Land of Israel. The Sages in the West, the Land of Israel, say in the name of Rabbi Zeira that the reason for the mishna’s ruling is: As a result of the fact that this litigant chooses one judge for himself, and that litigant chooses one judge for himself, and the two judges choose one more judge for themselves, the true judgment will emerge. Since each party chooses his own judge, and together the two judges select the additional judge, this will lead to a verdict that is just and true.

The true judgment will emerge: How will this procedure facilitate emergence of a true verdict? The Jerusalem Talmud (Sanhedrin 3:1) cites a statement of Rav Zeira in this regard: “Because he selected [his judge], [that judge] will plead in his favor.”

Some explain that the Gemara characterizes this ruling a true judgment due to its enforceability. The two parties will obey the court’s decision because they know that had the judge they selected been able to proffer a claim in their favor, he would have done so (Rashi). Even one who is found liable to pay will acknowledge that the ruling did not result from bias, but rather because the court realized they had no alternative but to rule against him (Rivan). Some add that a court selected in this way will feel freer to explore the merits of each claim, because its members were selected by both parties (Rashi).  

Having drawn a conclusion regarding the meaning of the text of the mishna, the Gemara seeks to ascertain the reason for the halakha: What is different about this procedure, i.e., that the selection of the judges is performed specifically in this manner, with each side choosing a judge? 