the fifth principle:

This principle reveals the heart of the matter: in Islamic law, what is unknown is treated as nonexistent or beyond one’s capacity. Allah, glorified and exalted, says:

“Allah does not burden a soul beyond its capacity.”

And He, exalted, says:

“So fear Allah as much as you are able.”

The Prophet, may Allah bless him and grant him peace, said:

“When I command you to do something, do as much of it as you can.”

Thus, whenever Allah commands us to do something, that command is conditional upon our having the ability and opportunity to carry it out. Whatever we are unable to ascertain or carry out is therefore no longer required of us. For this reason, the Prophet, may Allah bless him and grant him peace, said concerning lost property:

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

This lost property belonged to someone who had lost it. When identifying its owner proved impossible, the Prophet, may Allah bless him and grant him peace, said:

“It is Allah’s property, which He gives to whomever He wills.”

This indicates that Allah willed to remove that owner’s ownership of it and give it to the finder who had publicly announced it for a year. The imams agree that, after announcing it for a year, the finder may give it in charity. He may also take ownership of it if he is poor. But may he take ownership of it if he is wealthy? There are two well-known views on this. The position of al-Shāfiʿī and Ahmad is that this is permissible, whereas Abū Hanīfah does not permit it.

If a man dies and no heir of his is known, his property is used for the benefit of Muslims, even if he actually has an unidentified heir. Indeed, if the heir is subsequently identified, his property is to be handed over to him, although, before he was identified, disbursing it to its recipient was permissible