Abu al-Minhal (may Allah have mercy on him) said: I asked Sayyiduna Abdullah bin Umar (may Allah be pleased with them both): A man to whom I owe a debt said to me: Pay me the debt before its time and I will waive part of the debt for you. Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) forbade him from it and said: The Commander of the Believers, Sayyiduna Umar (may Allah be pleased with him), forbade us from selling ready goods in exchange for a debt.
A hadith with a connected chain has also been narrated about this, and there is weakness in its chain.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 11140