How are items that are neither measured nor weighed, such as cloth, animals, and counted items, treated regarding exchange?
Chapter on Riba (Usury) and Exchange (Sarf)
Al-Mughni
Book of Sales
Primary text
For items that do not have an established standard of measure or weight in the Hijaz, nor resemble items customarily measured or weighed—such as textiles, animals, and countable items like nuts, eggs, pomegranates, cucumbers, and other vegetables and greens, and fruits like quinces, apples, pears, and peaches—if equivalence (tamāthul) is required in their exchange, equivalence by weight is considered because it is more concise. This is the view mentioned by Al-Qadi regarding fresh fruits and one opinion among the companions of Al-Shafi'i.
Supporting text
The alternative view among the companions of Al-Shafi'i is that equivalence should be based on what can be measured by volume (kayl), as the origin lies in the four primary categories of measure, and the branch should revert to its origin, which mandates prohibiting exchange with unequal measure. However, the ruling must follow the more concise method, which is weight, as it is considered simpler in cases where volume measurement is impractical.