[The Ruling on Taking Furnishings Blown from the Rooftop of a House]

Answer – and Allah is the One who grants success: Those furnishings must be returned by whoever has them in his hand, due to His saying the Exalted: “Indeed, Allah commands you to return trusts to their rightful owners…” [al-Nisāʾ:58] and the like of such verses that forbid consuming people’s wealth wrongfully and forbid mutual wrongdoing. Thus, whoever has those taken furnishings in his hand is obliged to return them immediately, whether he is the one who gave the order or the one who carried it out.
The other party must also strive to return them to their owner, or obtain release from him and ask him for pardon. That is because rectifying what was corrupted by the sin is a condition of repentance, by evidence of His saying the Exalted: “Indeed, those who hide what We have sent down of clear proofs and guidance after We made it clear for the people in the Book – those are cursed by Allah and cursed by those who curse, except for those who repent and correct themselves and make evident (what they concealed) – those, I will accept their repentance, and I am the Accepting of repentance, the Merciful.” [al-Baqarah:159–160]
Moreover, in the words of the scholars of the madhhab there is that which indicates that liability is incumbent upon everyone in whose hand (the item) has been, meaning that the owner of the furnishings has the right to claim from each one in whose hand they have been, and that one who has had them in his hand is not absolved by returning them to someone else who is not their owner.
I say: That is because everyone in whose hand they have been is commanded to return them to their owner, by evidence of His saying the Exalted: “Indeed, Allah commands you to return trusts to their rightful owners…” [al-Nisāʾ:58] and by evidence of what has been narrated from the Prophet, May Allah bless him and his family and grant them peace, that he said: “The hand is responsible for what it has taken until it returns it,” or as he said.
Whoever returns what was taken to someone other than its owner has not complied with what is in the verse and the ḥadīth and has not fulfilled what is required; rather, he is still required to return it to its people – and its people are its owner.
If it is said: A person may buy a commodity, then it later becomes clear that it was stolen. What then is the ruling regarding the buyer, given his ignorance, and the absence of the seller – and the price of the commodity may be high?
We say: What is required is that the commodity be returned to its owner, and what is required of the seller is that he return the price to the buyer.
However, the scholars of the madhhab have said: The seller is not required to return the price to the buyer except in two cases:
1. If the buyer returns the commodity to its owner by a judicial ruling of the judge based on legal proof (bayyinah).
2. If he returns the commodity by order of the seller.
If he returns it without these two conditions, the seller is not required to return the price.

Source: Min Thimār al-ʿIlm wa al-Ḥikmah vol.2