Hammad bin Salama حماد بن سلمة · The Chapters on Business Transactions

"If two (separate) authorized persons make a sale (of the same thing), then the first transaction is the one that is valid. "

"O Allah, bless my nation early in the morning.' "

"I said to 'Abdullah bin 'Umar: 'Can I pay in advance for a date palm before it bears fruit?' He said: 'No.' I said: 'Why not?' He said: 'A man paid in advance for a grove of trees during the time of the Messenger of Allah (ﷺ), before they had produced any fruit, and they did not bear anything that year. The purchaser said: 'They belong to me until they produce but the seller said: 'I only sold the trees…