The lender then told the third party, "If I don't pay the balance by such-and-such date, give the document to the lender." This meant that he forfeited the partial payment. In the end, he did not pay. Rabbi Yossi says that the third party should give the loan document to the lender. Rabbi Yehudah says that he should not give it back because the borrower never really meant it.
After much deliberation, the law is not like Rabbi Yossi - promises like this one are not binding.
Art: Pieter van Veen, his son Cornelis and his clerk Hendrick Borsman by Jan van Ravesteyn