English: advance purchase of goods or buildings
Alternate spelling: Istisna’a, Istisna’ah
Definition: A contract of acquisition of goods by specification or order, where the price is paid in advance, or progressively in accordance with the progress of a job. For example, to purchase a yet to be constructed house, payments would be made to the builder according to the stage of work completed. This type of financing, along with Salam, is used as a purchasing mechanism, and Murabahah and Bai Bithaman Ajil are for financing sales.