What is the ruling on the ownership of a device and the right of the buyer who bought it from an unknown seller, given that the buyer does not know the seller's whereabouts, and the claimant has not sworn an oath to his ownership of the device?

If the claimant's right to the trousseau is established by evidence, it must be returned to him, based on the Almighty's saying: "Indeed, Allah commands you to render trusts to whom they are due," and on the Prophet's (peace be upon him) saying: "On the hand is what it has taken until it renders it." However, if his right is not established, then there is no obligation to return it. In the case of returning the trousseau and the claimant's right being proven, the amount paid to the seller becomes a debt owed by him. If it is impossible to reclaim it from him in this world, it will be rendered on the Day of Judgment through good deeds or by having sins placed upon him.