מאי טעמיה דרבי אליעזר אלא לאו בדלא שוי שיעור זוזי ובדשמואל קא מיפלגי
what is the reasoning of Rabbi Eliezer, who holds that although the collateral was lost, the debtor is still liable to pay? Rather, is it not a case where the collateral was not worth the amount of money that he lent him? And accordingly, they disagree with regard to the ruling of Shmuel. Rabbi Akiva holds in accordance with the opinion of Shmuel, that if the collateral is lost the entire debt is canceled, and Rabbi Eliezer disagrees with this opinion.
לא בדלא שוי כ"ע לית להו דשמואל והכא בדשוי שיעור זוזי ובדרבי יצחק קא מיפלגי דאמר רבי יצחק מנין לבעל חוב שקונה משכון שנאמר (דברים כד, יג) ולך תהיה צדקה
The Gemara rejects this suggestion: No, in a case where the collateral was not worth the value of the loan everyone is of the opinion that the ruling is not in accordance with the opinion of Shmuel. But here the dispute is with regard to a case where the collateral was worth the amount of money that he lent him, and they disagree with regard to the opinion of Rabbi Yitzḥak. As Rabbi Yitzḥak says: From where is it derived that a creditor acquires collateral given to him and is considered its owner as long as the item is in his possession? As it is stated with regard to a creditor who returns the collateral to the debtor for his personal use: “And it shall be a righteousness for you” (Deuteronomy 24:13).
אם אינו קונה משכון צדקה מנין לו מכאן לבעל חוב שקונה משכון
Rabbi Yitzḥak infers: If the creditor does not acquire the collateral, then from where is his righteousness? If the collateral is not his, the creditor would not be giving up anything of his own. From here it is derived that a creditor acquires the collateral. Rabbi Eliezer disagrees with this opinion, maintaining that the creditor has the halakhic status of an unpaid bailee with respect to the collateral, so that he is exempt from paying restitution if it is stolen or lost. He can therefore collect the entire debt from the debtor. Rabbi Akiva agrees with the opinion of Rabbi Yitzḥak, and holds that since the creditor acquires the collateral, he bears financial responsibility to pay its value in the event of its loss. Therefore, he must deduct the value of the collateral when collecting payment of the debt.
לימא דרבי יצחק תנאי היא ותיסברא אימור דאמר רבי יצחק שמשכנו שלא בשעת הלואה משכנו בשעת הלואה מי אמר
The Gemara asks: If so, shall we say that the opinion of Rabbi Yitzḥak is the subject of a dispute between tanna’im? The Gemara answers: And how can you understand that? Say that Rabbi Yitzḥak says that a creditor acquires the collateral in a case where he took the collateral from him not at the time of the loan, but afterward, in order to induce him to return the loan, as described in the context of the aforementioned verse. But in a case where the creditor took the collateral from him at the time of the loan, does Rabbi Yitzḥak say that he has acquired it?
אלא משכנו שלא בשעת הלואתו כולי עלמא לא פליגי דאית להו דרבי יצחק והכא במשכנו בשעת הלואתו
Rather, in a case where he took the collateral from him not at the time of the loan, everyone agrees that the opinion of Rabbi Yitzḥak is accepted, and here, the dispute between Rabbi Eliezer and Rabbi Akiva is with regard to a case where he took the collateral from him at the time of the loan.
ובשומר אבדה קמיפלגי דאיתמר שומר אבדה רבה אמר כשומר חנם
And they disagree with regard to the halakhic status of one who is safeguarding a lost item that he found but has not yet returned. As it was stated: With regard to one who is safeguarding a lost item, Rabba says that his halakhic status is like that of an unpaid bailee, who is exempt from paying restitution in the event that the item is lost or stolen,