Sa’if 1, Mechaber: Two persons borrowed money from one lender, purchased something from one seller. (Rama: Or received a deposit in trust from one depositor.) Irrespective of whether the transaction was recorded in writing or not, each person is deemed an arev, a guarantor for the obligations of the other. This is the halacha even if there was no express stipulation to this effect.
Accordingly, if one of the borrowers has no assets, the lender may collect the entire amount of the loan from the guarantor. If, however, both borrowers have assets, all the laws of a guarantor apply and the lender may not collect the entire loan from the guarantor but must collect half from borrower. If, however, the two borrowers explicitly stipulated that each was an arev kablan for the debt of the other, the lender can collect the entire loan from any of the two borrowers he chooses.
The borrower who repaid the lender the entire loan has a claim against the co-borrower for repayment of his half of the loan. (Rama: Accordingly, if two persons borrowed and one of them repaid the entire loan, he is deemed to have repaid fifty per-cent of it on the co-borrower’s behalf.)
Ner Eyal: This Sa’if deals with three cases. In the first, a person lends money to two people. In the second, a person sells one item to two persons on credit. In the third, a person deposits something of value for safekeeping with two persons. The plaintiff then sues the defendants for payment of the money or for the return of the goods. In all three cases there was nothing stipulated to indicate which of the two would be responsible for the repayment of the money or for the return of the goods.
In all three cases, the halacha deems each defendant to have guaranteed to the plaintiff half the loan the other defendant owes. We assume the plaintiff would not have lent the money to them or deposited the goods with them unless he received from both of them a joint undertaking of repayment or for the return of the goods. The plaintiff relied on this joint undertaking that if one of the two defendants would be unable to repay him, he could proceed against the other.
Accordingly, when attempting to collect, the plaintiff must proceed against each defendant for half the amount claimed. It is only if one of the defendants does not have the assets to pay his half that the plaintiff may proceed against the second defendant for the entire amount. Even then, he may only do this after he has taken an oath. He must swear that he attempted to collect half from the other defendant but was unsuccessful in doing so because he had no assets. The borrower who paid the entire loan can then claim from his co-borrower the fifty per cent he advanced on his behalf.
Generally, one who pays the debts of another is deemed to have volunteered to do so and has no claim for reimbursement. The borrower can argue that there was no need to pay the loan on his behalf. He would have managed to appease the lender and convince him to waive the loan. However, this does not apply to the case of two co-borrowers. This is because both parties, by becoming guarantors for each other, agreed that each would have the authority to repay the co-borrower’s portion of the loan.
If after the death of both borrowers, the heirs of one of them find among their deceased father’s papers a cancelled promissory note that indicates their father repaid the entire loan, this does not give them an automatic claim for reimbursement against the heirs of the co-borrower. It is possible the deceased father may have reimbursed his co-borrower before his death and forgotten to record it on the promissory note.
The lender, who received repayment of the entire loan from one of the borrowers, cannot argue that the additional money he received from the co-borrower was in respect of another loan he made him and not in respect of payment for the co-borrower. He may not, on the basis of this argument, continue to proceed against the defaulting borrower. It is an unrebuttable presumption that the additional half he received from the guarantor was in respect of the co-borrower who defaulted.