ولا يجوز التصرف في رأس المال ولا في المسلم فيه قبل قبض
Translation: Disposition of the capital or the goods owed is not permitted before possession.
Quduri bars dealings in both the advance capital and the future deliverable before the relevant possession. The required first receipt of the price cannot be bypassed by treating an unreceived amount as though it were already at the seller's disposal.
This is not a universal ban on spending personally owned money. The restriction concerns transactions involving the specific countervalue before the legally required receipt in that sale. The position after valid receipt is distinct.