A person asked Sayyiduna Abdullah bin Umar (may Allah be pleased with them both): If someone has a fixed-term debt upon another, and the debtor says, "Take a lesser amount from me in cash," and the creditor agrees to it? So Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) considered this disliked and forbade it.
Hadith Referenceموطا امام مالك رواية يحييٰ / كتاب البيوع / 1380