Musnad Ahmad 314

‘Uthman ibn ‘Umar and Abu ‘Amir narrated to us; he said: Malik narrated to us, from al-Zuhri, from Malik ibn Aws ibn al-Hadathan, who said: I brought some dinars of mine intending to exchange them. Talhah ibn ‘Ubayd Allah met me, exchanged them with me, and took them. He said, ‘Wait until my treasurer, Salm, arrives.’ Abu ‘Amir said: ‘From al-Ghabah.’ And he said regarding all of it: ‘hand to hand.’ I asked ‘Umar ibn al-Khattab, may Allah be pleased with him, about that, and he said: I heard the Messenger of Allah, peace and blessings be upon him, say: ‘Gold for silver is usury unless it is hand to hand; wheat for wheat is usury unless it is hand to hand; barley for barley is usury unless it is hand to hand; dates for dates are usury unless it is hand to hand.’