A type of khiyar (option) which comes into effect if the parties to the contract of sale (aqd al-ba’i) mutually agree to postpone the specification of the object of sale for a designated period, conferring on either party the option of specifying the underlying object. For example, a person may purchase one out of three vehicles owned by the same seller, with the option to specify which one within a period of three days.

According to Hanafis, this option is valid based on istihsan (juristic preference) as it meets a legitimate need of contracting parties. Other schools of thought, namely Shafi’is and Hanbalis, considered this option invalid in view of the state of ignorance/ lack of information (jahalah) it gives rise to.

Khiyar al-ta’yeen is an Arabic term (خيار التعيين) that translates as”option to specify” “option of specification”.