A seller says: “You may buy all the mangoes on this tree except 10 ratls that I will retain.”
The 10-ratl reservation is numerically specified, but the unharvested and unseparated remainder has not been identified in the way needed for the sale.
Classical commentary explains the prohibition through uncertainty in the subject remaining for the buyer. Knowing the number withheld does not by itself make the remainder sufficiently determined.
Opening interactive controls...
Kitab al-Buyu: Fruit Sales, Ripeness, Cutting and Reserved Quantities
A seller says: “You may buy all the mangoes on this tree except 10 ratls that I will retain.”
The 10-ratl reservation is numerically specified, but the unharvested and unseparated remainder has not been identified in the way needed for the sale.
Classical commentary explains the prohibition through uncertainty in the subject remaining for the buyer. Knowing the number withheld does not by itself make the remainder sufficiently determined.