אית ליה דררא דממונא ולההוא אית ליה דררא דממונא הכא אי דמר לא דמר ואי דמר לא דמר
he has financial involvement [derara], and for that one, i.e., the seller, he has financial involvement. Since each of them has a definite claim to owning the offspring, as each of them owned the cow or maidservant at one point, it is reasonable for the court to divide the offspring between the two parties. By contrast, here, in the case of Rav Naḥman, if it belongs to this Master it does not belong to that Master, and if it belongs to that Master it does not belong to this Master. Only one of the two litigants has any claim to the property, as it belonged either to the ancestors of this one or of that one. Therefore, a ruling to divide it would not be appropriate.
אמרי נהרדעי אם בא אחד מן השוק והחזיק בה אין מוציאין אותה מידו דתני רבי חייא גזלן של רבים לאו שמיה גזלן
The Sages of Neharde’a say: In a case where two parties disputed the ownership of a certain property and the court ruled that whoever is stronger prevails, if one from the marketplace who had no claim came and took possession of it, the court does not remove it from his possession, as Rabbi Ḥiyya teaches (Tosefta, Bava Kamma 10:14): A robber of the public, meaning a robber whose victim is unknown, is not called a robber. Since it is unclear whom he robbed, no one is able to demand payment. Here too, since it is unclear whose property it is, neither can demand that it be taken from the robber.
רב אשי אמר לעולם שמיה גזלן ומאי לא שמיה גזלן שלא ניתן להשבון:
Rav Ashi said in disagreement: Actually, he is called a robber, and the property is taken from him, and what is meant by: He is not called a robber? It means that the stolen item is not subject to being returned, and consequently he is unable to fully atone, as he does not know whom to repay.
חזקתן שלש שנים מיום ליום וכו': א"ר אבא אי דלי ליה איהו גופיה צנא דפירי לאלתר הוי חזקה אמר רב זביד ואם טען ואמר לפירות הורדתיו נאמן והני מילי בתוך שלש אבל לאחר שלש לא
§ The mishna teaches with regard to certain types of property that their presumptive ownership is established by use of a duration of three years from day to day. The Gemara comments: Rabbi Abba says: Nevertheless, there are cases where presumptive ownership is established immediately. For example, if the prior owner himself lifted a basket of fruit from that field for the possessor, that immediately is sufficient to establish the presumption of ownership, and the prior owner can no longer lodge a protest. Rav Zevid says: But if the prior owner stated a claim and said: I brought him down into my field solely to consume the produce, e.g., as a sharecropper, he is deemed credible. And that halakha, that the prior owner is deemed credible were he to state such a claim, applies only if he stated it within three years of when the other took possession, but after three years he is not deemed credible.
א"ל רב אשי לרב כהנא אי לפירא אחתיה מאי הוה ליה למעבד א"ל איבעי ליה למחויי
Rav Ashi said to Rav Kahana: If in fact he did bring him down into the field solely to consume the produce, what was there for him to do to prevent the possessor from establishing the presumption of ownership? Rav Kahana said to him: He should have protested during the first three years and publicized that he had granted the possessor rights to the produce alone.
דאי לא תימא הכי הני משכנתא דסורא דכתב בהו במשלם שניא אלין תיפוק ארעא דא בלא כסף אי כביש ליה לשטר משכנתא גביה ואמר לקוחה היא בידי הכי נמי דמהימן מתקני רבנן מידי דאתי ביה לידי פסידא אלא איבעי ליה למחויי הכא נמי איבעי ליה למחויי
The assumption that lodging a protest would be effective must be correct, since if you do not say so, then in the case of this mortgage according to the custom in Sura, a city in Babylonia, in which is written: At the completion of these years this land will be released to its prior owner without any need for the prior owner to give money, if the creditor were to hide the mortgage document in his possession and say: This land is purchased and that is why it is in my possession, here is it also the case that he would be deemed credible? That cannot be, as is it reasonable that the Sages would institute a matter, such as this type of arrangement, that people can be led by it to suffer a loss? Rather, in the case of the mortgage the debtor should have protested, and by not protesting, he causes his own loss. Here, too, in the case of the field, the owner should have protested.
אמר רב יהודה אמר רב ישראל הבא מחמת עכו"ם הרי הוא כעכו"ם מה עכו"ם אין לו חזקה אלא בשטר אף ישראל הבא מחמת עכו"ם אין לו חזקה אלא בשטר אמר רבא ואי אמר ישראל
§ Rav Yehuda says that Rav says: With regard to a Jew who comes to claim land due to having received it from a gentile, he is like a gentile in terms of which legal claims are available to him. Therefore, just as a gentile has the ability to establish the presumption of ownership only by means of a document, so too, a Jew who comes to claim land due to having received it from a gentile has the ability to establish the presumption of ownership only by means of a document. Rava said: And if the Jew said to a prior owner, who claims to still own the land: