Sulaiman bin Ali Rabee says: Abu Juza’ has narrated to us many times, he says: I asked Sayyiduna Ibn Abbas (may Allah be pleased with them both) about the exchange sale (bay’ sarf), he said: There is no harm if it is two for one, or more, or less. When I went for Hajj the next time, this elder was still alive, I came to him and asked again about the exchange sale. He said: It should be equal in weight. I said: You gave me the fatwa that it can be two for one, and I have been giving this fatwa since then? He said: That was my opinion, now Sayyiduna Abu Saeed Khudri (may Allah be pleased with him) has narrated to me (that this is usury), so I have abandoned my opinion because of this hadith of the Messenger of Allah (peace and blessings be upon him).