The ruling on selling cement before taking possession of it to an entity that sells it for a profit

The questioner : Honorable Shaykh, there are entities that buy cement from the cement factory. After the factory receives the price, it issues documents to the entity specifying the quantity, quality, and delivery date of the cement. These documents bear the entity's name. The entity then sells these documents to truck owners for a price higher than what it paid, and the truck owners take delivery directly from the factory based on the documents bearing the entity's name. Is it permissible for the truck owner to buy from the entity, given that the factory approves this method and it is the standard practice among cement sellers?

The Shaykh : What is the situation? A person buys a large quantity from the factory, then sells it to another person for more than the price agreed upon with the factory. There are several prohibitions here. First, it is selling a debt to someone other than the one who owes it, because this cement you bought from the factory is a debt fixed in its liability. It is not permissible to sell a debt to anyone other than the one who owes it, absolutely.
Second, it is selling what has not entered into your guarantee, because this cement at the factory does not enter into your guarantee unless you take possession of it. If you sell it before taking possession, you have sold something that has not entered into your guarantee. The Prophet (peace and blessings be upon him) forbade selling what has not been guaranteed. Third, the Prophet (peace and blessings be upon him) said to Hakim al-Hizam and this is . And what makes you think that this factory might not go bankrupt, or burn down, or be struck by something that prevents it from delivering what you agreed upon in your contract with it? Therefore, we hold that this transaction is forbidden, and that if a person buys something from someone, he should not sell it until he takes possession of it, and then he may sell it to whomever he wishes.