His statement, “Otherwise, its value on the day it becomes unavailable,” means: if compensation with an equivalent is not possible, then he is liable for its value on the day it became unavailable.

Suppose that he destroyed a fungible item, but an equivalent item later became unavailable. For example, he unlawfully took it in Muḥarram and destroyed it while similar items were still available in the market. Then, in Rabīʿ, it disappeared from the market, and in Jumādā the owner demanded compensation from him. What is he liable for now? Is he liable for its value at the time compensation is demanded, or at the time it became unavailable? The author says: “Otherwise, its value on the day it becomes unavailable.” The reasoning behind this view is that once an equivalent became unavailable, liability for its value became established; therefore, he must compensate its value as it stood at the time of unavailability.

Yet there would also be grounds for saying that he is liable for its value at the time it is recovered from him. This is because the basic principle is that an equivalent remains established as a debt upon him until he delivers it. If it becomes unavailable between the time of destruction and the time of recovery, it may not be unavailable at the time of recovery. It may, for example, become unavailable in Rabīʿ but be available again in Jumādā. In that case, we hold him liable for the equivalent; but if it is unavailable, then for the value of the equivalent at the time of recovery. For what is originally established as a debt upon the usurper is the equivalent, and unavailability may exist at one time but not at another.

His statement, “A non-fungible item is compensated according to its value on the day it is destroyed,” is because liability for value in the case of a non-fungible item is established from the time of usurpation. Thus, if this non-fungible item is destroyed, its value is assessed at the time of its destruction, since before it is destroyed it remains the property of its owner, and any increase or decrease in its value belongs to the owner.

However, the scholars differed as to whether a usurped item must be compensated for a fall in market price, or not. This has already been discussed.

His statement, “If grape juice turns into wine, then the equivalent is due”: a person unlawfully takes grape juice