Is the sale of a palm tree bearing dates for dates permissible, or for another palm tree bearing dates?
Chapter on Riba (Usury) and Exchange (Sarf)
Al-Mughni
Book of Sales
Primary text
There are two differing views on selling a palm tree with dates for dates or for another palm tree with dates. The first view permits the sale, chosen by Abu Bakr, because the dates are not the primary object of the sale. The second view prohibits it. The rationale for both views mirrors that discussed in the preceding issue concerning the sheep.
Supporting text
The Qadi chose the view of prohibition, distinguishing this case from the lactating sheep by asserting that the fruit (dates) can be validly specified for sale while being known, unlike the milk in the sheep. This distinction, however, is deemed inoperative because what causes prohibition invalidates the transaction even if it can be sold separately, whereas what is permissible does not invalidate the transaction even if it can be sold separately, citing the example of a slave's wealth.