12. Ali ibn Ibrahim has narrated from his father from Ibn Abi ‘Umayr from Hammad from al-Halabiy who has said the following:

“Abu ‘Abd Allah , has said, ‘Exchanging dry dates with fresh ones is not valid; dry dates are dry and fresh are not dry. When it dries it shrinks. Exchanging barley with wheat is also not valid unless it is in equal measures.’ He (the Imam) said, ‘Measuring is one and the same. It is detestable to exchange one Qafiz (a certain unit of measurement) of almond for two or one Qafiz of dates for two Qafiz of dates. However, it is valid to exchange one Sa‘ of wheat with two Sa‘ of dates and one Sa‘ of dates with two Sa‘ of raisins when they are different and in the form of dry fruits. It applies to foodstuff and fruits in the same manner.’ Or that he (the Imam) said, ‘It is not harmful if goods are exchanged as long as they are not exchanged in measurements and weighing.’”