ACCORDING TO THE GEMARA ON 88A "1. Denying a loan is like admitting that it was not paid." SO WHY DOES RAV NACHMAN BELIVE THE BORROWER TO SAY THAT HE PAID. WITNESSES SAY HE DIDN'T BORROW (MEANING HE ALSO DIDN'T PAY THE LOAN BACK), THE BORROWER SAYS I BORROWED AND PAID IT BACK. SO WE BELIEVE HIM THAT HE OWES IT AND THE WITNESSES WHEN THEY SAY HE DIDN'T PAY IT BACK, AND HE WOULD NOW HAVE TO PAY THE DEBT. SO WHY DOES RAV NACHMAN SAY HE DOESN'T HAVE TO?
SHMUEL HOENIG, NEW YORK, USA
Are you refering to Rav Nachman on 19a when he tells the Malveh: be Mekayem the Shtar and then go to court? If so, Rashi explains that without Kiyum of witnesses which OK the Shtar there is only the OK of the Loveh- but he said he paid back so haPeh sheAsar Hu haPeh sheHiteir and the Shtar is worthless. Witnesses never said that he didn't pay back. There are witnesses in the Shtar which say there was a loan, but they don't talk about if it was returned Normally ,if the Malveh holds the Shtar that means it wasn't collected yet but here we only would honor the Shtar and its witnesses because of the Loveh- and he said in the same breath that its worthless because he paid back.
R Nachman on 19b says that if witnesses say thisShtar is Amanah- that we didn't witness a loan and we only signed as preparation for afuture loan they are not believed. They cannot ruin the assumtion that the Shtar is legal(only written after the loan) and therefore the Shtar Remains intact and can be used to collect with We don't believe the Loveh that he paid back since the Shtar is still in the Malveh's hands (there was Kiyum here without the Loveh)
All the best,