The first: it must have a benefit.

The second: the benefit must be permissible.

The third: that permissibility must not be dependent on necessity.

Thus, by our statement, “permissible to benefit from,” we exclude things whose benefit is prohibited, such as instruments of amusement, which may not be sold because their benefit is prohibited. The same applies to wine, because its benefit is prohibited.

And by our statement, “it must have a benefit,” we exclude that which has no benefit, such as insects; therefore, their sale is invalid. If someone were to collect cockroaches in a container and say to another person, “I am selling you these cockroaches,” it would not be permissible to sell them, because they have no benefit. But if he collected locusts in a container and said, “I am selling you these locusts,” then the sale would be permissible, because they have a permissible benefit. Thus, insects may not be sold, because they have no benefit.

Our statement, “without necessity,” excludes that which may be benefited from due to a need, such as a dog. Benefit may be taken from a dog, but not without restriction; rather, only for a need, such as hunting, guarding crops, and guarding livestock. Therefore, selling a dog is invalid, even if it is a hunting dog, and even if it is trained, despite the fact that it has a permissible benefit, because the Prophet, may Allah’s peace and blessings be upon him, forbade the price of a dog (1).

As for a cat, it does in fact have benefit: it eats mice, insects, geckos, and cockroaches. Some cats circle around a person when he is asleep, and you find its chest making a sound and moving; and when any insect comes near a sleeping person—