Musannaf Ibn Abi Shayba 13:853

Abu Bakr narrated to us, he said: Waki’ narrated to us, he said: Hammad ibn Salamah narrated to us, from al-Hasan ibn ‘Ata’ al-Madini, from his father, that a man sold an item to a man, and the buyer claimed a defect, so he disputed with him before ‘Uthman ibn ‘Affan. The buyer said: "Swear by Allah that you did not sell it to me [with a defect]." The seller said: "I swear by Allah, I sold it to you and I do not know of any defect in it." He said: So ‘Uthman said: "The man has treated you fairly."