Muhammad bin al-Sabah محمد بن الصباح البزاز الدولابي · The Chapters on Business Transactions

"Do not meet the traders on the way, and whoever meets any of them and buys from him, the vendor has the choice of annulling the transaction when he comes to the marketplace.''

"Do not sell fruits until they have ripened."'

"Whoever buys food, let him not sell it until he has taken full possession of it."

"I heard 'Umar bin Al-Khattab say: 'The Messenger of Allah (ﷺ) said: "Exchanging gold for gold is usury unless it is done on the spot. (Exchanging) wheat for wheat is usury, unless it is done on the spot. (Exchanging) barley for barley is usury unless it is done on the spot. (Exchanging) dates for dates is usury, unless it is done on the spot."