Abu Hurairah · Commercial Transactions (Kitab Al-Buyu)

I heard Messenger of Allah (ﷺ) say: But between them are certain doubtful things which many people do not recognize. He who guards against doubtful things keeps his religion and his honor blameless, but he who falls into doubtful things falls into what is unlawful.

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…

"He (the Prophet) purchased a calf from a caravan, but he had no money with him. He then sold it with some profit and gave the profit in charity to the poor and widows of Banu 'Abd al-Muttalib. He then said: I shall not buy anything after this but only when I have money with me.

The Messenger of Allah (ﷺ) forbade the sale of fruits for dried dates, but gave license regarding the 'araya for its sale on the basis of a calculation of their amount. But those who buy them can eat them when fresh.

The Messenger of Allah (ﷺ) forbade selling palm-trees till the dates began to ripen, and ears of corn till they were white and were safe from blight, forbidding it both to the buyer and to the seller.

The Prophet (ﷺ) forbade sale of fruits for a number of years. One of the two narrators (Abu al-Zubair and Sa'id b. Mina') mentioned the words "sale for years" (bai' al-sinin instead of al-mu'awamah).