Nasai

´It was narrated that abu Al-Minhal said:` "Sharik sold some silver on credit for me. He came to me and told me. And I said: 'This is not correct.' He said; 'By Allah, I did this transaction in the market and no one criticized me .' So I went to Al-Bara bin Azib and asked him about that. He said: 'The Prophet came to us in Al-Madinah and we used to do this kind of transaction, but he said: Whatever is hand to hand, there is nothing wrong with it, but whatever is on credit, is Riba. Then he said to me: 'Go to Zaid bin Arqam.' So I went to him and asked him, and he said the same thing."

´Abu Al-Minhal said:` " I asked Al-Bara bin 'Azib and Zaid bin Arqam and they said: 'We were merchants at the time of the Messenger of Allah and we asked the Prophet of Allah about money exchange. He said: "If it is done hand to hand there is nothing wrong with it, but if it is done on credit then it is not right."

´Abu Al-Minhal said:` "I asked Al-Bara bin 'Azib about money exchange. He said: 'Ask Zaid bin Arqam, for he is better than me and more knowledgeable.' So I asked Zaid and he said: 'Ask Al-Bara for he is better than me and more knowledgeable.' And they both said: 'The Messenger of Allah forbade (selling) silver for gold on credit."'