Bai’ al-Salam (بيع السلم)
A contract of sale whereby the purchase price is paid in advance and the goods are delivered later. This method of sale is an exception to the rule that no sale can be affected unless the goods are in existence at the time of the bargain, provided that the goods are defined and the date of delivery is fixed. The objects of this method of sale must be items that can be specifically described as to quantity, quality and specifications. The amount paid upfront as salaf cannot be called back before the merchandise due to be delivered.