Sunan Ibn Majah, Chapter: The Chapters on Business Transactions

"I heard Abu Said Al-Khudri say: 'A Dirham for a Dirham and a Dinar for a Dinar.' So I said: 'I heard Ibn 'Abbas say something other than that.' He said: 'But I met Ibn 'Abbas and said: "Tell me about what you say concerning exchange is it something that you heard from the Messenger of Allah (saw) or something that You found in the Book of Allah?" He said: "I did not find it in the Book of Allah, and I did not hear it from the Messenger of Allah; rather Usamah bin Zaid told me that the Messenger of Allah (saw) said: "Usury is only in credit."