Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) said: Habban bin Munqidh was a weak man; he had the mark of a deep wound on his head. The Messenger of Allah (peace and blessings be upon him) said: "He has the option for three days in whatever he buys." His tongue was also not sound. He (peace and blessings be upon him) said: "Sell, and say: There is no deception." I used to hear him saying: "No deception, no deception." He would buy something and bring it home, and his family would say: This is expensive. He would say: The Messenger of Allah (peace and blessings be upon him) has given me the option in my sale.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10458