1) UNDERSTANDING THE POSITION OF RAV PAPA
QUESTION: The Gemara quotes Rav Papa who says that one who wants to collect a loan which was not written in a Shtar may collect from the heirs of the borrower, but he may not seize property from Lekuchos, people who bought property from the borrower after the loan was taken. Rav Papa explains that the lender may collect from the heirs in order to encourage lenders from lending money ("she'Lo Tin'ol Deles" -- "so that the door not be shut in the face of borrowers"). However, the lender may not collect from Lekuchos, because a verbal loan (one not written in a Shtar) does not publicize the loan and thus the Lekuchos had no way of knowing that the property they bought was collateralized to a loan.
The Gemara in a number of places records a dispute about "Shibuda d'Oraisa." Is every lien binding mid'Oraisa? The opinion that maintains that every lien is mid'Oraisa would also maintain that even when one lends money without a Shtar, he should be entitled to collect his money from either the borrower or from his heirs. That opinion does not need the reasoning of "she'Lo Tin'ol Deles." Accordingly, Rav Papa, who says that the only reason why the lender may collect from the borrower's heirs is "she'Lo Tin'ol Deles," apparently maintains that a Shibud is not d'Oraisa. However, in Kidushin (13b) Rav Papa says the same statement he says here about collecting from heirs, but he says that the reason why one may collect from heirs is that "Shibuda d'Oraisa"! How are the words of Rav Papa to be reconciled?
(a) The RITVA says in the name of others that the correct text in the Gemara in Kidushin is "Rav Papi," not "Rav Papa."
(b) The Ritva quotes RABEINU TAM who explains that there are two different versions of what Rav Papa said, similar to the way a Gemara often quotes an alternate version with the words, "Ika d'Amri." (Y. MONTROSE)
2) WHAT IS AN "AREV D'BEIS DIN"?
OPINIONS: Maseches Bava Basra concludes with a discussion of which type of Arev (guarantor) needs a Kinyan. The Gemara states that an "Arev d'Beis Din" does not need a Kinyan, since he has absolute intention to make himself an Arev as a result of the Hana'ah (benefit) that he receives from the fact that people look upon him as a trustworthy person.
What is the exact case of an "Arev d'Beis Din," and who exactly looks upon him as a trustworthy person?
(a) The RASHBAM (DH Arev d'Beis Din) explains that an "Arev d'Beis Din" is merely someone who co-signs a loan in front of Beis Din. Since the Beis Din accepts him as a co-signer, Beis Din gives the impression that he is a trustworthy person. The Rashbam apparently understands that the case of the "Arev d'Beis Din" is an ordinary loan.
(b) The RAMBAM (Hilchos Malveh v'Loveh 25:2) writes that the case involves a person who actually co-signs for the Beis Din. The Beis Din is about to begin the process of forcing a borrower to pay, and this person tells the Beis Din that he will sign as a guarantor for the Beis Din that the lender will receive his money in due time. The fact that the Beis Din accepts his guarantee shows that the Beis Din trusts him, and as a result of that benefit the guarantor does not need a Kinyan.
(It is important to note that the fact that the guarantor receives benefit is not a pre-condition for his status as an Arev, but rather it enables Beis Din to assume that the guarantor committed himself fully under conditions which normally would not elicit a total commitment to pay back the loan. This is despite the fact that the Gemara in Kidushin (7a) says that if a woman tells a man to give someone else a Maneh and she will thereby become betrothed to him, the Kidushin is valid because of the "law of Arev." See the PNEI YEHOSHUA to Kidushin 7a, and the TZITZ ELIEZER 5:25, ch. 30, for more on this subject.) (Y. MONTROSE)