Abu Salih (may Allah have mercy on him) says: I sold wheat in the market and fixed a time for its payment. Then I intended to go to Kufah, and they proposed to me that I waive part of the debt and they would pay before the due time. I mentioned this to Sayyiduna Zayd bin Thabit (may Allah be pleased with him), and he said: "I do not instruct you to consume such wealth or to let others consume it."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 11138