To what extent is it permissible to buy and sell cement invoices, knowing that the goods have not yet been received from the company and were later sold for a profit? And what should be done if the transaction is impermissible?

This transaction that occurred between your friend and the company is either:

- A manufacturing contract (Istisna'): In this case, selling the manufactured item before taking possession of it is impermissible, because it is a sold item that has not been seized.

- A sale: However, the buyer did not pay the price, nor did he take possession of the sold item. Thus, your friend's sale to you would be a sale of something he has not taken possession of, which is impermissible.

- A promise to purchase: In this case, your friend sold you something he does not own, and selling what one does not own is Haram by consensus, based on the Prophet's (peace and blessings be upon him) saying: "Do not sell what is not with you."

In any case, a فسخ-able (fasid) sale, which is agreed upon as being فسخ-able, does not materialize in the first place. The buyer returns the merchandise and the seller returns the price. If the merchandise is no longer available, the buyer returns its value and the seller returns the price.