this is that the Prophet (peace and blessings be upon him) appointed Urwah ibn al-Jaʿd (may Allah be pleased with him) to purchase a sacrificial animal for him and gave him one dinar. He bought two sacrificial animals for one dinar, then sold one of them for a dinar. He had been commissioned to purchase one sacrificial animal, but he bought two—and this undoubtedly involved benefit. Then he sold one of the two animals for a dinar, and this likewise involved benefit. He returned to the Prophet (peace and blessings be upon him) with his dinar and a sheep, so the Prophet said, “O Allah, bless his trade.” (1) Thereafter, whenever he traded in anything, he made a profit through the blessing of the Prophet’s supplication. According to the author’s view, this transaction would be invalid. The correct view, however, is that it is permissible and effective if the owner ratifies it.
If someone asks: Is it permissible for a person to proceed with selling someone else’s property without his permission?
We say: It is permissible when there is an indication to that effect. For example, if I know that my companion wishes to sell his house, and someone comes wishing to buy it for one hundred thousand, while it is worth ninety thousand, and I know that the owner of the house wants to sell it, then I may sell it for one hundred thousand, because this serves his interest. The man wishes to sell his house for ninety thousand, so if someone comes to buy it for one hundred thousand, this is beneficial. Therefore, I may proceed with the transaction. Otherwise, the basic rule is that one may not proceed with such a transaction, because it is someone else’s property. But if you see that it serves an interest, then there is no harm in it.
His statement, “if he purchases with his specific asset”: this is less serious than the first case, because a person does not mind whether he receives this dirham or that dirham. Thus, if he purchases with the specific asset belonging to another, the established school holds that it is invalid, because it is like selling that specific asset: the contract was concluded with respect to the specific dirhams owned by someone else.