Bava Metzia 2a
בבא מציעא ב׳ א — ד"ה וְלִיתְנֵי ״אֲנִי מְצָאתִיהָ״
Bava Metzia 2a:6
The sugya begins from the Mishnah about finding lost objects and tests what counts as valid acquisition by mere seeing. It distinguishes between two cases in the Mishnah and develops the principle that sight alone does not yet create legal acquisition.
וְלִיתְנֵי ״אֲנִי מְצָאתִיהָ״, וַאֲנָא יָדַעְנָא דְּכוּלָּהּ שֶׁלִּי! אִי תְּנָא ״אֲנִי מְצָאתִיהָ״, הֲוָה אָמֵינָא: מַאי ״מְצָאתִיהָ״ – רְאִיתִיהָ. אַף עַל גַּב דְּלָא אֲתַאי לִידֵיהּ – בִּרְאִיָּה בְּעָלְמָא קָנֵי, תְּנָא: ״כּוּלָּהּ שֶׁלִּי״ – דְּבִרְאִיָּה לָא קָנֵי. וְלִיתְנֵי ״כּוּלָּהּ שֶׁלִּי״ וְלָא בָּעֵי ״אֲנִי מְצָאתִיהָ״! אִי תָּנֵי ״כּוּלָּהּ שֶׁלִּי״ הֲוָה אָמֵינָא: בְּעָלְמָא דְּקָתָנֵי ״מְצָאתִיהָ״ בִּרְאִיָּה בְּעָלְמָא קָנֵי, תְּנָא ״אֲנִי מְצָאתִיהָ״ וַהֲדַר תְּנָא ״כּוּלָּהּ שֶׁלִּי״ דְּמִמִּשְׁנָה יַתִּירָה אַשְׁמְעִינַן דִּרְאִיָּה לָא קָנֵי.
The Gemara asks: But let the tanna teach a case where each one merely claims: I found it, and I would know that the intention of each litigant is to claim: All of it is mine. The Gemara answers: If the tanna would teach only that each one claimed: I found it, I would say that what is the meaning of the claim: I found it? It means: I saw it. In other words, he is claiming that he saw the item first, and he believes that even though it did not reach his possession, he acquired it through mere sight. Since it would have been possible to think that this is an effective claim, the tanna teaches that the litigant states definitively: All of it is mine, to teach that one does not acquire a lost item through sight alone. The Gemara asks: But if that was the objective of the tanna, let him teach that each party need only state: All of it is mine, and the litigant would not need to say: I found it. The Gemara answers: If the tanna had taught that it is sufficient for each party to claim only: All of it is mine, I would say that in general, when the tanna teaches that one claims: I found it, he means that the finder acquires the item through mere sight. Therefore, he taught that the litigants claimed: I found it, and he then taught that the litigants claimed: All of it is mine, to teach that only when the litigants each make both of these claims does the court divide the item, as from the superfluous expression in the mishna he teaches us that one does not acquire the item through sight alone.