ومن باع صبرة طعام كل قفيز بدرهم جاز البيع في قفيز واحد عند أبي حنيفة إلا أن يسمي جملة قفزانها
Translation: Whoever sells a heap of grain at one dirham per qafiz: according to Abu Hanifah, the sale is valid for one qafiz only unless the total number of qafiz in the heap is stated.
The seller identifies the heap, but a per-qafiz price leaves the aggregate consideration dependent on an unstated number of measures.
Under Abu Hanifah's view, one definite measure is valid, while stating the full quantity removes the uncertainty surrounding the remainder. This differs from selling the entire identified pile for one fixed lump sum.