If a commodity is sold in an immediate exchange transaction, both the buyer and the seller can claim the commodity and the payment from each other after the transaction and take possession of them. The handing over of a moveable commodity, such as a rug or clothes, and an immoveable commodity, such as a house or land, is realised by relinquishing the item and making it available to the other party in a way that he could have disposal over it if he wanted.
This would be different in different cases.