subject to the rules of riba; on this there is consensus. If it is not subject to those rules, there are two views. Likewise, the Prophet, may Allah bless him and grant him peace, permitted purchasing fruit once it begins to ripen, on condition that it be left to mature, even though its remaining growth has not yet been created or seen. He thus treated what did not yet exist, had not been created, and was not known as incidental to it. People likewise need to sell these plants while they are still in the ground.

A similar case is the sale of crops grown in patches, such as melons, cucumbers, qiththāʾ (a kind of cucumber), and the like. Some followers of al-Shāfiʿī, Ahmad, and others hold that these may only be sold one picking at a time.

Many scholars among the followers of Mālik, Ahmad, and others, however, hold that they may be sold without this restriction, in the customary manner. This is the correct view, for ordinarily they cannot be sold in any other way. Selling them one picking at a time is either impossible or difficult, since one picking cannot be clearly distinguished from another: much of the produce cannot be picked, and its picking may be deferred. Thus, selling the crop of a patch once it shows signs of ripening is like selling an orchard’s fruit once it begins to ripen, even though some of what is sold has not yet been created or seen.

For this reason, when some of a tree’s fruit begins to ripen, this counts as the onset of ripening for the rest of it, by scholarly consensus. It also counts as the onset of ripening for all fruit of the same kind in the orchard, according to the stronger of the two scholarly views, which is also the majority view. Indeed, according to one of the two scholarly views, it counts as the onset of ripening for all the orchard’s fruit that is customarily sold together. These issues, along with others mentioned in this answer, are discussed at length elsewhere.