כיון שמסר לו מפתח קנה once he has conveyed the key to him, he has acquired it.
ה"ד אי בכספא ליקני בכספא אי בחזקה ליקני בחזקה לעולם בחזקה ובעי למימר ליה לך חזק וקני וכיון שמסר לו מפתח כמאן דאמר ליה לך חזק וקני דמי Here too, the Gemara asks: What are the circumstances involving this sale? If it was a transaction by payment of money, then let him acquire it by paying money. If it was by taking possession of it, let him acquire it by taking possession. What is the significance of transferring the key? The Gemara answers: Actually, the transaction occurred by taking possession, and in that case, the seller usually must say to him: Go, take possession, and thereby acquire it for yourself. And in this case, once he conveys the key to him, he is considered like one who says to him: Go, take possession, and thereby acquire it.
אמר ריש לקיש משום ר' ינאי המוכר עדר לחבירו כיון שמסר לו משכוכית קנה Similarly, Reish Lakish says in the name of Rabbi Yannai: With regard to one who sells a flock of sheep to another, once he conveys the mashkukhit to the buyer, he has acquired the flock.
ה"ד אי במשיכה ליקני במשיכה אי במסירה ליקני במסירה לעולם במשיכה ובעי למימר ליה לך משוך וקני וכיון דמסר לו משכוכית כמאן דאמר ליה לך משוך וקני דמי The Gemara asks: What are the circumstances of this case? If the transaction occurred by pulling the flock into his possession, then let the buyer acquire it by pulling. If it was by conveying it, let the buyer acquire it by the seller conveying it. The Gemara answers: Actually, it was a transaction by pulling, and in that case, the seller usually must say to him: Go, pull it and acquire it for yourself. And in this case, once he conveys the mashkukhit to him, he is like one who says to him: Go, pull it and acquire it.
מאי משכוכית הכא תרגמו קרקשתא ר' יעקב אומר עיזא דאזלא בריש עדרא כדדרש ההוא גלילאה עליה דרב חסדא כד רגיז רעיא על ענא עביד לנגדא סמותא: The Gemara asks: What is this mashkukhit? Here, in Babylonia, they translate it as a bell [karkashta] that the shepherd rings and whose sound the flock follows. Rabbi Ya’akov says: It is referring to the goat that goes at the front of the flock that they follow. The Gemara notes: This explanation of Rabbi Ya’akov is similar to that which a certain Galilean taught in the presence of Rav Ḥisda concerning this goat: When a shepherd is angry with his flock, he renders the goat leading [lenaggada] them, i.e., the mashkukhit, blind. Similarly, when God is angry with the Jewish people, he appoints unsuitable leaders for them.
מתני׳ כסהו הראשון ובא השני ומצאו מגולה ולא כסהו השני חייב כסהו כראוי ונפל לתוכו שור או חמור ומת פטור לא כסהו כראוי ונפל לתוכו שור או חמור ומת חייב MISHNA: The mishna lists several halakhot that pertain to damage classified as Pit: In the case of a pit that the first person who passed by covered after using it, and then the second came to use it and found it uncovered after the cover fell off or was damaged, and he did not cover it, the second one is liable for damage caused by the pit. If the owner covered the pit appropriately and an ox or a donkey fell into it and died, he is exempt. If he did not cover the pit appropriately and an ox or a donkey fell into it and died, he is liable.
נפל לפניו מקול הכרייה חייב לאחריו מקול הכרייה פטור If a man was digging or widening a pit, and an ox passing by fell forward into it in fright due to the sound of the digging, he is liable. If it fell backward into the pit due to the sound of the digging, he is exempt.
נפל לתוכו שור וכליו ונשתברו חמור וכליו ונתקרעו חייב על הבהמה ופטור על הכלים If an ox and its accoutrements, i.e., the vessels it was carrying, fell into the pit and the vessels were broken, or if a donkey and its accoutrements fell in and the accoutrements were torn, the owner of the pit is liable for damage to the animal caused by the pit, but he is exempt from liability for damage caused to the vessels, by Torah edict.
נפל לתוכו שור חרש שוטה וקטן חייב בן או בת עבד או אמה פטור: If an ox that was impaired by being deaf, or an ox that was an imbecile, or an ox that was very young fell into the pit, he is liable. If a boy or a girl, a Canaanite slave or a Canaanite maidservant fell in, he is exempt, since there is a Torah edict that the digger of a pit is liable only for damage caused to an animal.
גמ׳ וראשון עד אימת מיפטר אמר רב בכדי שידע ושמואל אמר בכדי שיודיעוהו ורבי יוחנן אמר בכדי שיודיעוהו וישכור פועלים ויכרות ארזים ויכסנו: GEMARA: With regard to the first case in the mishna, the Gemara asks: And until when is the first person exempt if the pit is later uncovered? Rav says: He is exempt from liability for the time necessary for him to become aware that it became uncovered. Once this time has passed, he bears responsibility. And Shmuel says: He is exempt for the time necessary for others to realize that the pit is uncovered and inform him. And Rabbi Yoḥanan says: He is exempt for the time necessary for others to inform him that the cover has fallen down and for him to hire workers and cut cedar trees to make a suitable cover and cover it. After this period of time has passed, the first bears responsibility.
כסהו כראוי ונפל לתוכו שור או חמור ומת פטור: כיון דכסהו כראוי היכי נפל אמר ר' יצחק בר בר חנה שהתליע מתוכו § The mishna teaches: If he covered the pit appropriately and an ox or a donkey fell inside and died, he is exempt. The Gemara asks: Since he covered the pit appropriately, how did it fall in? Rabbi Yitzḥak bar bar Ḥana says: This is a case where the cover rotted from the inside, and he could not have known that the cover was damaged. Therefore, he is not responsible for damage caused as a result.
איבעיא להו כסהו כסוי שיכול לעמוד לפני שוורים ואין יכול לעמוד בפני גמלים ואתו גמלים וארעוה ואתו שוורים ונפלי ביה מאי אמרי היכי דמי אי דשכיחי גמלים פושע הוא ואי דלא שכיחי גמלים אנוס הוא A dilemma was raised before the Sages: If he covered it with a cover that is able to withstand the weight of oxen but cannot withstand the weight of camels, which are heavier, and camels came and weakened it, and subsequently oxen came and broke the weakened cover and fell into the pit, what is the halakha? The Sages said in response: What are the circumstances? If camels are commonly found there, he is negligent, since he should have constructed the cover suitably for camels as well. And if camels are not commonly found there, then he is a victim of circumstances beyond his control if by chance they did come and weaken the cover.
לא צריכא דאתו לפרקים מי אמרינן כיון דאתיין לפרקים פושע הוא דאיבעי ליה אסוקי אדעתיה או דלמא כיון דהשתא מיהת ליכא אנוס הוא The Gemara answers: No, it is necessary in a case where camels come occasionally, in which case the question effectively becomes: Do we say that since they come occasionally, he is considered negligent, since he should have anticipated their coming? Or perhaps since now, in any event, there are no camels, he is a victim of circumstances beyond his control.
ת"ש כסהו כראוי ונפל לתוכו שור או חמור ומת פטור ה"ד אילימא כראוי לשוורים וכראוי לגמלים היכי נפול אלא לאו כראוי לשוורים Come and hear a possible proof from the mishna: If he covered the pit appropriately, and an ox or a donkey fell into it and died, he is exempt. Now what are the circumstances? If we say that he covered it appropriately for oxen and appropriately for camels, then how did they fall in? Rather, is it not the case that he covered it with a covering that was appropriate for oxen