An Unnamed Man Who Brought Dates from Khaybar RA

This unnamed man once brought the Prophet ﷺ a large bag of especially fine dates, around the time of Khaybar, a land famous for its date groves. Impressed, the Prophet ﷺ asked whether all the dates of Khaybar were like these. The man answered, "No. This date is such-and-such; we purchase one sa' of this for three sa' of normal dates." The Prophet ﷺ told him not to do so, but to sell the ordinary dates for money and then use the money to buy the better ones. The exchange is the origin of the prohibition of riba al-fadl: certain commodities, such as dates and wheat, may be exchanged for the same kind only in equal amounts.