- Which expressions imply ערבות, and which imply קבלנות
Rav Huna says that if a potential guarantor said, "הלוהו ואני ערב" – “Lend him and I will be an ערב,” or “Lend him and I will pay,” or “Lend him and I will be liable,” or “Lend him and I will give (payment),” these are all expressions of an ordinary ערב. If he said, "תן לו ואני קבלן" – “Give him the money and I will be a קבלן,” or “Give him and I will pay,” etc., these are expressions of a קבלן (from whom the lender may collect outright, even if the borrower has property). Because he asked the lender to “give” the money rather than “lend” it, we consider the loan being made on the guarantor’s behalf. If he said, “Lend him and I will be a קבלן,” or “Give him and I will be an ערב,” (thus using terms of opposite implications), Rav Yitzchak ruled that we follow the קבלנות or ערבות term used. Rav Chisda said that all the expressions above are commitments for קבלנות, except “Lend him and I will be an ערב” (i.e., both terms of ערבות). Rava said all the expressions above are commitments for ערבות, except “Give him and I will give (payment)” (or “…and I will be a קבלן”).
- Two reasons an ערב cannot be reimbursed by יתומים
An ערב for orphans paid the lender without notifying the orphans and came to be reimbursed. Rav Pappa said: פריעת בע"ח מצוה – the payment of a debt is a mitzvah, ויתמי לאו בני מיעבד מצוה נינהו – and minor orphans are not required to perform mitzvos until they become adults (even if the loan was recorded in a שטר, the orphans’ new debt to reimburse the ערב is an oral debt). Rav Huna brei d’Rav Yehoshua held orphans would be compelled to perform the mitzvah of repaying a debt, and explained differently why the ערב cannot collect from the orphans: אימר צררי אתפסיה – I say perhaps [the borrower] gave [the lender] bundles of money as payment before he died. The Gemara notes two practical differences between these reasons: כשחייב מודה – where the liable person (the father) admitted before his death that he owed the money, or דשמתוהו ומת בשמתיה – where [Beis Din] banned him for refusing to pay, and he died while still banned. In both cases, we know he did not pay the debt, but the orphans would still be exempt from the mitzvah of reimbursing the ערב according to Rav Pappa.
- An ערב or קבלן becoming obligated for a kesubah or ordinary debt
The Gemara discusses which kind of guarantor is bound to his commitment to guarantee various debts. ערב דכתובה – regarding an ordinary ערב to guarantee a kesubah, דברי הכל לא משתעבד – everyone agrees he is not obligated to keep his commitment, as the Gemara will explain. Regarding a קבלן for an ordinary debt, everyone agrees he is obligated. Amoraim argue about a קבלן for a kesubah, and an ערב for an ordinary debt. One holds these guarantors only obligate themselves if the debtor had property (and it is unlikely he will have to pay), and the other holds he must keep his commitment even if the debtor did not have property. The halachah is that in all cases, he is bound by his commitment to guarantee the debt, except for an ערב for a kesubah, who is exempt from paying even if the husband did have property. The Gemara explains: מצוה הוא דעבד – [the ערב] was merely doing a mitzvah of convincing her to get married without fear of her kesubah not being paid, ולאו מידי חסרה – and he did not cost her anything in her getting married (in contrast to an ערב for a loan).