Sa’if 5, Mechaber: If the lender claims repayment of the loan after the maturity date or at the end of the day the loan fell due and the defendant raises the defense that he repaid the loan before the maturity date (see Shach Sa’if Katan 19 ibid), the defendant is believed, provided he takes the Shevuat Heiset oath of denial.
Ner Eyal: The Sma wonders why the Mechaber finds it necessary to repeat that the defendant who gets sued for the repayment of a loan at the end of the day the loan fell due may raise the defense that he repaid the loan before it fell due. The Mechaber has already said that in Sa’if 78:4. The fact that the Mechaber adds in this Sa’if that the debtor is only believed to say that he paid before the maturity date if he takes a Shevuat Heiset oath of denial is no reason for the Mechaber to repeat himself, because that is obvious. Any defendant who denies a claim in its entirety must take the Shevuat Heiset oath of denial.