Sunan Ibn Majah, Chapter: The Chapters on Business Transactions

"Abdullah bin Shaddad and Abu Barzah had a dispute about paying in advance. They sent me to Abdullah bin Abu Awfa to ask him about it. He said: 'We used to make payments in advance at the time of the Messenger of Allah (saw) and the time of Abu Bakr and Umar, for wheat, barley, raisins and dates, to people who did not yet possess those things.' I asked Ibn Abza, and he said something similar."