Gharar

Gharar (Arabic: غرر‎‎) literally means uncertainty, hazard, chance or risk. It is a negative element in mu'amalat fiqh (transactional Islamic jurisprudence), like riba (usury) and maysir (gambling). One Islamic dictionary (A Concise Dictionary of Islamic Terms) describes it as "the sale of what is not present" — such as fish not yet caught, crops not yet harvested. Similarly, author Muhammad Ayub says that "in the legal terminology of jurists", gharar is "the sale of a thing which is not present at hand, or the sale of a thing whose aqibah (consequence) is not known, or a sale involving hazard in which one does not know whether it will come to be or not".

According to Sami Al-Suwailem, "researchers in Islamic finance" do not agree on the "precise meaning" of gharar, although there is not necessarily great difference among the Islamic schools of jurisprudence (madhab) in the term's definition.

The Hanafi legal school defines gharar as "that whose consequences are hidden", (according to Sami Al-Suwailem). According to Md Akther Uddin, scholars of Hanafi school of fiqh (Islamic jurisprudence have defined gharar as “something which its consequence is undetermined.” Sarakhsi, an Islamic scholar of the Hanafi school, described gharar as "“anything that the end result is hidden or the risk is equally uncommon, whether it exists or not.”

Similarly, the Shafi legal school defined gharar (according to Sami al-Suwailem) as "that whose nature and consequences are hidden" or "that which admits two possibilities, with the less desirable one being more likely." Scholars of Shafi’i fiqh have described it as “something which in its manner and its consequence is hidden.

The Hanbali school defined it as "that whose consequences are unknown" or "that which is undeliverable, whether it exists or not."Ibn Hazm of the Zahiri school of jurisprudence wrote "Gharar is where the buyer does not know what he bought, or the seller does not know what he sold."

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Wikipedia