Murabaḥah is a term for a sales contract where the buyer and seller agree on the markup, the ratio between the cost of a good or service and what?
Murabaha Murabaḥah, murabaḥa or murâbaḥah (Arabic: مرابحة‎ ‎ , derived from "ribh" Arabic: ربح‎ ‎ , meaning profit) is a term of "fiqh" (Islamic jurisprudence) for a sales contract where the buyer and seller agree on the markup (profit) or "cost-plus" price for the item(s) being sold. In recent decades it has become a term for a very common form of Islamic (i.e. "shariah compliant") financing, where the price is marked-up in exchange for allowing the buyer to defer payment (a contract with deferred payment being known as "bai-muajjal"). "Murabaha" financing is similar to a rent-to-own arrangement in the non-Muslim world, with the intermediary (i.e. the lending bank) retaining ownership of the item being sold until the loan is paid in full. There are also Islamic investment funds and sukuk (Islamic bonds) that use "murabahah" contracts.
Sürsat Sürsat was a form of food requisitioning with price controls, used by the Ottoman Empire to provide consumables for its armed forces. It was related to nüzül; sürsat was initially an obligation for the public to provide food and other supplies at a pre-fixed price which was unlikely to be favourable, or might even be merely symbolic. Istira was basically the same obligation, but supposedly at "market" price. Over time, nüzül, sürsat, and istira were all transformed into extraordinary cash taxes on people living near the route travelled by the army.