subject to riba, because it is neither explicitly mentioned nor analogous to what is explicitly mentioned. Rather, it is like other beverages that are drunk besides milk.
“The criterion for measuring by volume is the custom of Medina, and for weighing, the custom of Mecca during the time of the Prophet, peace and blessings be upon him. Whatever has no established custom in those two places is determined according to the custom of its own locality.”
His statement, “The criterion for measuring by volume is the custom of Medina, and for weighing, the custom of Mecca during the time of the Prophet, peace and blessings be upon him,” means that the determination of whether something is measured by volume or by weight is referred to the customs of Mecca and Medina. With regard to measuring by volume, we refer to the custom of Medina. Thus, if an item was measured by volume in Medina but weighed in Mecca, we consider it measured by volume according to Medina. And if it was weighed in Mecca but measured by volume in Medina, we refer to Mecca. Accordingly, the ruling differs depending on whether a person is in Mecca or Medina: if he is in Medina, then the measure is that of Medina; and if he is in Mecca, then the weight is that of Mecca. If the two cities agree that an item is measured by volume or by weight, then it is regarded as such, whether one is in Mecca or Medina. What is authoritative is the custom of Mecca during the lifetime of the Messenger, peace and blessings be upon him—a matter of which many people may be unaware.
The scholars, may Allah have mercy on them, have mentioned criteria for what is measured by volume and what is weighed. Among them is the point mentioned earlier: every liquid is measured by volume.
Another is that whatever cannot feasibly be measured by volume is assessed by weight, such as bread, tightly packed compressed dates, and the like. It is assessed by weight, but this does not remove it from being classified as something measured by volume.
There are also things for which no established measure by volume or weight is known in Mecca or Medina. To what, then, do we refer? The author said: