According to the most authoritative Arabic dictionaries, the word Istisna‘ is derived from the word Sana’a which literally means “making, manufacturing, or constructing something.” According to Ibn Manzur in Lisan al-‘Arab, Istisna‘ occurs “when someone invited, induced or caused another to make the thing”.
The word has been used also in the Qur’an and Sunnah, such as,
“And you see the mountains, thinking them rigid, while they will pass as the passing of clouds. [It is] the work of Allah, who perfected all things. Indeed, He is Acquainted with that which you do.” [Al-Quran, surah Al-Naml, verse 88],
Or in the Sunnah where it is reported that the Prophet had ordered someone to make a ring for him “Istana’ Khataman Linafsihi”. He ordered that it should be made for him [Refer Ibn Yacoub al-Fayrozabadi from al-Qamus al-Muhit].
Although the dictionary meaning of the word is to make a thing, its juridical meaning is disputed among the jurists. Some jurists define it by giving examples; others tackle it through its essence and attributes. For instance, al-Kasani defines it as:
“When one orders a craftsman to prepare a piece of furniture for a determined price, to be delivered later, or one may engage a cobbler to make a pair of shoes for a fixed price“ [Refer al-Kasani in Bada’i al-Sani Fi Tartib al-Sharai].
On the other hand, Istisna‘ is also defined as “a contract with a manufacturer to make something” [‘Ala’ al-Din al-Samarkhandi in Tuhfat al-Fuqaha’] or “a contract in a commodity on liability with the provision of work” [al-Kasani in Bada’i al-Sani Fi Tartib al-Sharai] or “to order a manufacturer to produce a specific commodity in a specific way”.
The Majella follows this trend by defining Istisna‘ as “to contract with a skilled person to make something”. The person who makes the thing is called “Sani'” and the person who causes it to be made “Mustasni” and the thing made “Masnu'” [Refer the Mejjele in Art]. It is also defined as if someone said “make a thing of this sort for so many piastres for me” to one of the skilled persons who make those things, and he accepts.
The sale by Istisna‘ is a concluded contract. For example, if a purchaser shows his foot to a bootmaker and says, “make me a pair of boots, for so many piastres of such a sort of leather” and the latter accepts, or if there is a bargain with a ship’s carpenter to make a ship or a boat and its length and breadth and qualities and things required are explained, the Istisna‘ becomes a complete contract [Refer The Mejjele in Art].
However according to al-Zarqa’, after he studied some of these definitions, concluded that they are imprecise and incomplete. He defined Istisna‘ as a contract of selling a manufacturable thing with an undertaking by the seller to present it manufactured from his own material, with specified descriptions and at a determined price. [Refer Mustapha Ahmad Al-Zarqa’ in ‘Aqd al-Istisna’ Wa mada Ahammiyyatuhu Fi al-Istithmarat al-Islamiyah al-Mu’asira]
The last definition shows that Istisna‘ is a contract and not just a promise as claimed by some of the Hanafi jurists. The contract if Istisna‘ is valid only for objects that can be made, therefore it is invalid for corn, wheat, barley or fruit.