Sa'id bin Jubayr سعيد بن جبير الأسدي · The Book of Financial Transactions

Muawiyah sold a cup of gold or silver for more than its weight. Abu Ad-Darda' said: "I heard the Messenger of Allah forbid such transactions unless it was like for like."

"On the Day of Khaibar I got a necklace containing gold and gems, and I wanted to sell it. Mention of that was made to the Prophet and he said: 'Take it apart, and then sell it."'

"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…

"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."'

"The Messenger of Allah forbade selling silver for silver and gold for gold, unless it was of equal amounts. And he told us to sell gold for silver however we wanted, and silver for gold however we wanted.

"The Messenger of Allah forbade us from selling silver for silver unless it was of equal amounts, or selling gold for gold unless it was of equal amounts. The messenger of Allah said: 'Sell gold for silver however you want, and silver for gold however you want."'

"The Messenger of Allah said: 'No man is bound by a transaction involving the sale of something that he does not possess.'''

"I asked the Prophet "O Messenger of Allah, a man may come to me and ask me to sell him something that I do not have. Can I sell it to him then go and buy it from the market?' He said: 'Do not sell what you do not have.'''