Question

A litigant who has found a strong halakhic source against himself—must he disclose what he knows to the judges? I had innocently assumed the answer was obviously yes, because otherwise he is simply a thief. But I heard from an elderly learned relative in my extended family that this once actually happened to him: he knew the judge’s position on the issue, which was built on an interpretation of a passage in the Jerusalem Talmud derived by force of a difficulty, and that learned relative—who was the litigant—had in his possession another Jerusalem Talmud passage that sheds light on the first one, showing that a certain amora there follows his own position as stated in the second Jerusalem Talmud passage, and not in accordance with the Jewish law, so that the novel interpretation was unnecessary. He did not reveal this to the judge, and the case was decided in favor of that litigant. According to him, once the religious court has ruled, then certainly the money in his hands is legitimately his, and moreover people enter into transactions on the understanding that the judges’ rulings define the matter as it stands. Years later he saw that that same judge found the second Jerusalem Talmud passage, or was told about it, and indeed retracted his view. Whether the story actually happened or not, I don’t know—the man is already old, and his stories have gotten strange over the years—but the idea is interesting: is there really a possibility that a litigant may conceal a source or halakhic reasoning that he sees the judges do not know?