al-Laith bin Sa'd الليث بن سعد · The Chapters on Business Transactions

"We went out with the Messenger of Allah (ﷺ) and the people were trading early in the morning. He called them: 'O merchants!' and when they looked up and craned their necks, he said : 'The merchants will be raised on the Day of Resurrection as immoral people, apart from those who fear Allah and act righteously and speak the truth (i.e. those who are honest)."'

"The Messenger of Allah (ﷺ) was treated with cupping and he told me to give the cupper his wages."

"When two men enter into a transaction, each of them has the choice (of annulling it) so long as they have not yet parted and are still together, or one of them has given the option or choice to the other. Once he has accepted the terms of the other, then the transaction is binding. If they part after concluding the transaction and neither of them has rescinded the transaction then the transaction is binding.”

the Messenger of Allah (ﷺ) said: "Whoever sells a palm tree that has been pollinated, its fruits belong to the seller, unless the purchaser stipulated a condition. And whoever buys a slave who has wealth, his wealth belongs to the seller, unless the purchaser stipulated a condition."

the Messenger of Allah (ﷺ) ruled that what a slave earns belongs to his guarantor.

Xthe Messenger of Allah (ﷺ) cursed the one who consumes usury, the one who pays it, those who witness it and the one who writes it down.

"When the Prophet (ﷺ) came (to Al-Madinah), they used to pay in advance for dates, two or three years in advance. He said: 'Whoever pays in advance for dates, let him pay for a known amount or a known weight, to be delivered at a known time.’”