Arabic (البيع النافذ) for a type of al-bay’ al-muna’aqid (enforceable contract of sale). By definition, it is a contract of sale (al-ba’i) that is not contingent on any right of a third party. In other words, the effect of such a contract is immediate. For example, ownership is an effect of sale, and it materializes at once, where the buyer becomes the rightful owner of the object of sale once the contract of sale is entered into. This is contrary to a contingent sale and an optional sale wherein ownership will not be effected unless contingency is fulfilled in the former and option is dropped in the latter.

This type of sale it is of two types: lazim (binding) and ghair lazim (non-binding). Al-bay’ al-lazim is a contract of sale that is associated with no options (to revoke) for any of the parties and al-bay’ ghair al-lazim is a contract of sale that may have at least one option for either party.