al-Zuhri ابن شهاب الزهري‎, محمد بن مسلم · Commercial Transactions (Kitab Al-Buyu)

On the authority of his father: I heard the Messenger of Allah (ﷺ) say in the Farewell Pilgrimage: "Lo, all claims to usury of the pre-Islamic period have been abolished. You shall have your capital sums, deal not unjustly and you shall not be dealt with unjustly. Lo, all claims for blood-vengeance belonging to the pre-Islamic period have been abolished. The first of those murdered among us whose blood-vengeance I remit is al-Harith ibn AbdulMuttalib, who suckled among Banu Layth…

The Prophet (ﷺ) said: After the grave sins which Allah has prohibited the greatest sin is that a man dies while he has debt due from him and does not leave anything to pay it off, and meets Him with it.

The Prophet (ﷺ) owed me a debt and gave me something extra when he paid it.

The Prophet (ﷺ) forbade the sale of fruits on the tree for fruits by measure, and sale of grapes for raisins by measure, and sale of harvest for wheat by measure.

The Prophet (ﷺ) forbade the type of sale which involves risk (or uncertainty) and a transaction determined by throwing stones.

The Prophet (ﷺ) forbade two types of business transactions and two ways of dressing. The two types of business transactions are mulamasah and munabadhah. As regards the two ways of dressing, they are the wrapping of the samma', and that when a man wraps himself up in a single garment while sitting in such a way that he does not cover his private parts or there is no garment on his private parts.

"Wearing the samma' means that a man puts his garment over his left shoulder and keeps his right side uncovered. Munabadhah means that a man says (to another): If I throw this garment to you, the sale will be certain. Mulamasah means that a man touches it (another's garment) with his hand and neither he unfolds it nor turns it over. When he touched it, the sale becomes binding.

The Messenger of Allah (ﷺ) forbade the leasing of land. I asked: (Did he forbid) for gold and silver (i.e. dinars and dirhams)? He replied: If it is against gold and silver, then there is no harm in it.

When the Prophet (ﷺ) conquered Khaibar. He then narrated it like the tradition of Zaid (b. Abu al-Zarqa'). This version has: He then assessed the produce of the palm-trees and said: I take the job of picking the fruit myself, and I shall give you half of (the amount) I said.