Dhakwan says: Sayyiduna Abu Sa'id Khudri (may Allah be pleased with him) sent me to Sayyiduna Ibn Abbas (may Allah be pleased with them both) and said: Ask him about the transaction of sarf (exchange of gold and silver), whether you have heard any hadith from the Messenger of Allah (peace and blessings be upon him) which we have not heard, or have you read anything in the Book of Allah which we have not read? He replied: I do not narrate any such hadith. The matter is that Sayyiduna Usama bin Zaid (may Allah be pleased with them both) has narrated that the Messenger of Allah (peace and blessings be upon him) said: There is no usury except in credit.