Rif Bava Kamma 22b {52a; 51b; 52a - b}

22b

{Bava Kamma 52a}
Gemara:

וכיון דכסהו כראוי היכי נפל
אמר רב יצחק בר בר חנה שהתליע מתוכו:

But since he covered it properly, how could the animal have fallen? Rav Yitzchak bar bar Chana said: That they {=the boards} decayed from within.

{Bava Kamma 51b}

אמר רבי אלעזר המוכר בור לחברו כיון דמסר לו דליו קנה
ה"ד אי בכספא ליקני בכספא ואי בחזקה ליקני בחזקה
אמרי לעולם בחזקה ובעי למימר ליה לך חזק וקנה וכיון שמסר לו דליו כמאן דאמר ליה לך חזק וקנה דמי:

Rabbi Eleazar said: If a man sells a pit to another, as soon as he hands over the cover of the pit to him, the conveyance is complete.
How so? If money was paid, why was the conveyance not completed by the money? If possession was taken [of the pit], why was the conveyance not completed by possession?
Say indeed, possession to have been taken [of the pit], and it was still requisite for the seller to say to the buyer, 'Go forth, take possession and become the owner', but as soon as he handed over the cover to him, this was equivalent [in the eyes of the law] to his saying to him, 'Go forth, take possession and complete the conveyance.'

אמר ריב"ל המוכר בית לחברו כיון שמסר לו מפתח קנה
ה"ד אי בכספא ליקני בכספא ואי בחזקה ליקני בחזקה אמרי לעולם בחזקה ובעי למימר ליה לך חזק וקנ' וכיון שמסר לו המפתח כמאן דאמר ליה לך חזק וקנ' דמי:

Rabbi Yehoshua ben Levi said: If a person sells a house to another,
{Bava Kamma 52a}
as soon as he hands over the key to him, the conveyance is complete.
How so? If money was previously paid, why was the conveyance not completed by the money? If possession was taken, why was the conveyance not completed by possession? We suppose that in fact possession was taken, and it was still requisite for the seller to say to the buyer, 'Go forth, take possession and become the owner', but as soon as he handed over the key to him, this was equivalent to his saying to him, 'Go forth, take possession and complete the conveyance.'

אמר רשב"ל משום רבי ינאי המוכר עדר לחברו כיון שמסר לו משכוכית לא צריך למימר ליה לך משוך וקנה דכמאן דאמר ליה לך משוך וקנה דמי מאי
משכוכית הכא תרגמו כרכשתא
רבי יעקב אמר עיזא דאזלא ברישא
כדדרש ההוא גלילאה עליה דרב חסדא כד רגיז רעיא על עאניה עביד להו נגידא סמיתא:

Rabbi Shimon ben Lakish said in the name of Rabbi Yannai: If a man sells a herd to his neighbour, as soon as he has handed over the mashchochit, he need not say to him "go, pull and acquire," for he is as if he said to him "go, pull and acquire."
What is a mashchochit? So did they translate it: The bell.
Rabbi Yaakov said: The goat that leads the herd.
As that Gililean expounded before Rav Chisda: when the shepherd becomes angry with his flock he appoints for a leader one which is blind.

נפל לפניו מקול הכרייה חייב לאחריו מקול הכרייה פטור:
איבעיא להו כסהו כיסוי שיכול לעמוד לפני שוורים ואין יכול לעמוד לפני גמלים ושכיחי גמלים והתליע מתוכו מהו
מי אמרינן מיגו דהוי פושע לגמלים הוי פושע לענין התלעה או דלמא לגבי התלעה אונס הוא
תא שמע נפל לתוכו שור חרש שוטה וקטן סומא ומהלך בלילה חייב פקח ביום פטור
ואמאי נימא מדהוי פושע לענין חש"ו הוי פושע נמי לענין פקח אלא לאו ש"מ לא אמר מיגו
שמע מינה:

"IF IT FELL FORWARD ON ACCOUNT OF THE NOISE OF DIGGING, THERE WOULD BE LIABILITY, BUT IF IT FELL BACKWARD ON ACCOUNT OF THE NOISE OF DIGGING, THERE WOULD BE EXEMPTION":
{Bava Kamma 52b}
It was a question to them: If he had covered it with a cover which was strong enough for oxen but not strong enough for camels, and camels are frequent there {an emendation based on the later gemara} and they weakened it {and then oxen came and fell into the pit}, what is the law?
Do we say that since he was negligent for camels, he was negligent in terms of weakening it, of perhaps in terms of weakening it, he is considered entirely accidental?
Come and hear: 'If there fell into it an ox that was deaf, abnormal, small, blind or while it walked at night time, there would be liability. But in the case of a normal ox walking during the day there would be exemption.'
But why? Let us say that since he was negligent in terms of the deaf, abnormal, or small animal, he was also negligent in terms of the normal one. Do we not deduce that we do not say "since?"
We indeed so deduce.