The second is taking possession of such property without the Lawgiver’s permission, even if its owner consents. This includes prohibited contracts and receipts of property, such as usury, gambling, and the like.

Whoever comes into possession of it must return it to the person entitled to it. If that proves impossible, an unknown person is treated as nonexistent. This is indicated by the Prophet’s statement, may Allah bless him and grant him peace, concerning lost property:

“If you find its owner, return it to him; otherwise, it is Allah’s property, which He gives to whomever He wills.”

The Prophet, may Allah bless him and grant him peace, thus explained that when lost property is known to belong to someone whose rights are protected by Islamic law, and has left his possession without his consent, but its owner cannot be found, Allah has given it to the person whom He enabled to acquire it through the lawful procedures for collecting lost property.

Likewise, Muslims agree that when someone dies without any known heir, his property is spent on the public interests of the Muslims. Yet most people must have some distant residuary heir; his identity, however, is unknown, with no prospect of discovering it, so he is treated as nonexistent. This is evident, and there are not two conclusive proofs by analogy like those we have mentioned from the Sunnah and consensus. For whatever cannot possibly be known or is entirely beyond our ability is, as far as we are concerned, equivalent to what does not exist. We are therefore charged only with what we know and are capable of doing.

When knowledge or ability is lacking—as in the case of someone who is insane or incapable—there is no difference, as far as our obligations are concerned, between an act we have not been commanded to perform and one we have been commanded to perform in general. Likewise, there is no difference, as far as our obligations are concerned, between property that has no owner to whom we have been commanded to deliver it and property that we have been commanded, in general, to deliver to its owner, when we lack knowledge of him or the ability