The Oral Talmud with Benay Lappe and Dan Libenson Episode 12

Rav Kahana says: In a Sanhedrin where all the judges saw fit to convict the defendant in a case of capital law, they acquit him. The Gemara asks: What is the reasoning for this halakha? It is since it is learned as a tradition that suspension of the trial overnight is necessary in order to create a possibility of acquittal. The halakha is that they may not issue the guilty verdict on the same day the evidence was heard, as perhaps over the course of the night one of the judges will think of a reason to acquit the defendant. And as those judges all saw fit to convict him they will not see any further possibility to acquit him, because there will not be anyone arguing for such a verdict. Consequently, he cannot be convicted. Rabbi Yoḥanan says: They place on the Great Sanhedrin only men of high stature, and of wisdom, and of pleasant appearance, and of suitable age so that they will be respected. And they must also be masters of sorcery, i.e., they know the nature of sorcery, so that they can judge sorcerers, and they must know all seventy languages in order that the Sanhedrin will not need to hear testimony from the mouth of a translator in a case where a witness speaks a different language. Rav Yehuda says that Rav says: They place on the Sanhedrin only one who knows how to render a carcass of a creeping animal pure by Torah law. The judges on the Sanhedrin must be so skilled at logical reasoning that they could even produce a convincing argument that creeping animals, which the Torah states explicitly are ritually impure, are actually pure. Rav said: I will discuss the halakha of the creeping animal and render it pure, i.e., I am able to demonstrate how it is possible to construct such a proof:

If a snake, which kills other creatures whose carcasses are impure and thereby increases impurity in the world, is itself nevertheless pure, as it is not included in the list of impure creeping animals, then concerning a creeping animal that does not kill and does not increase impurity, isn’t it logical that it should be pure? This argument is rejected: But it is not so; the logic of the halakha of a creeping animal is just as it is concerning the halakha with regard to an ordinary thorn, which can injure people or animals and can even kill and thereby increase impurity, but is nevertheless pure. It is therefore apparent that this consideration is not relevant to the halakhot of impurity.