Is the method mentioned for selling—represented by concluding a sale contract with the source on condition that the sale is void if the purchase order is not referred to the company—legitimate for avoiding "selling what you do not possess"? And is it considered a musawamah (bargaining) sale?

It is forbidden to sell what one does not own, except in a salam contract. Other alternatives include murabaha and agency with a fee. The scenario of purchasing the commodity desired by the customer and then selling it to him is valid, but the purchase contract must actually take place between the seller and the source of the commodity before selling it to the buyer. If the buyer is informed of the price and profit, it is a murabaha sale. If he is not informed of the price, it is a musawama (bargaining) sale, and both are permissible. As for the condition "the sale is void if the purchase order is not referred to us," it is invalid due to the unspecified duration. The correct approach is to purchase the commodity with an option of condition for a specified period (e.g., one week). If the buyer does not purchase, the commodity can be returned within the agreed-upon period. If the period expires and the sale is not rescinded, it becomes binding. Jurists have highlighted the permissibility of resorting to the option of condition to avoid selling what one does not own.