measurement by volume, it is not permissible. If we say that the effective cause is edibility, it is permissible; and if we say that the effective cause is measurement by volume together with edibility, it is likewise permissible.

If fruit is sold for the same type of fruit in unequal amounts, then, if we say that the effective cause is edibility, it is not permissible. If we say that the effective cause is measurement by volume, it is permissible; and if we say that the effective cause is measurement by volume together with edibility, it is permissible. Thus, the examples depend on the disagreement over defining the effective cause.

If someone were to say, “We concede that wheat, barley, and dates are edible, but what is to be said about salt?” Shaykh al-Islam answered that salt is used to improve food and is therefore ancillary to it. Hence it is said, “Grammar in speech is like salt in food.” Salt is among the adjuncts of food. On the basis of this reasoning, ribā also applies to spices used to improve food, because they are ancillary to it.

When we consider these three views, we find:

First: the closest of them to what is correct is this view. This is because, when we consider the six categories specified by the Messenger of Allah (peace and blessings be upon him), we find them to be edible commodities measured by volume.

Second: the basic principle governing buying and selling is permissibility. Therefore, we cannot prohibit for people that which is originally permissible until this is established clearly. Since nothing has been established except where both effective causes—measurement by volume and edibility—are present together, we say that everything else remains upon the original ruling. This was the view chosen by Shaykh al-Islam Ibn Taymiyyah (may Allah have mercy on him).

“Ribā al-faḍl (surplus ribā) is prohibited in every commodity sold by volume or weight when it is exchanged for the same type. Immediate settlement and taking possession are required. A commodity sold by volume may only be exchanged for the same type by volume, and a commodity sold by weight may only be exchanged for the same type by weight; nor may part of it be exchanged for another part by estimation. If the types differ, all three are permissible.”

His statement, “Ribā al-faḍl is prohibited in every commodity sold by volume or weight when exchanged for the same type,” is based on the view that the effective cause is measurement by volume and weight: measurement by volume in the four, and measurement by weight in