Firstly: Trade by sample [1711] A “sample” is an example of the thing, and its form is for the seller or broker to carry a small quantity from the measure or the weighted item (a sample) to the buyer until he sees it. If he likes it, he buys it. For example, coming to him with a bushel or a quarter bushel of wheat, saying, "I sell to you a similar quantity of wheat for such and such a price," and the contract is completed for the purchase of a similar quantity to the sample that the buyer saw. See Al-Qamus al-Muhit (1/208), Taj al-`Arus (6/249, 250), Tabyin al-Haqa’iq by Zayla`i (4/26), and Al-Sharh al-Mumti` by Ibn `Uthaymin (8/151).
Trade by sample is valid, and this was the position of the majority – the Hanafis, [1712] Tabyin al-Haqa’iq by Zayla`i (4/26) and Al-`Inayah by Babarti (6/342). Malikis, [1713] Sharh al-Zurqani `ala Mukhtasar Khalil (5/63) and Minah al-Jalil by `Ulaysh (4/484). Shafi`is [1714] It is valid according to the Shafi`is if the sample is included in the sale. Rawdat al-Talibin by Nawawi (3/373), Al-Majmu` by Nawawi (2/298), and Nihayat al-Muhtaj by Ramli (3/419, 420). – and a view in the Hanbali school of thought. [1715] Al-Mubdi` by Burhan al-Din Ibn Muflih (3/363) and Al-Insaf by Mardawi (4/213). This is because it is a customary practice for knowledge of some of a particular category to suffice for knowledge of the whole. [1716] Tabyin al-Haqa’iq by Zayla`i (4/26)

Secondly: The manufacturing (istisna`) contract
1. Defining “the manufacturing contract”
Linguistically: “Istisna`” is derived from the declension “sana`a”, “yasna`u”, “sun`a”, “fa huwa masnu`”, and a “sun`a” is a “work” or “action”, as in the Statement of Allah Exalted: “That is the work of Allah, who has perfected everything.” [1717] al-Naml, 88. “Istisna`” is the “ifti`al” form of “sani`ah”, and it implies “giving”, “honouring”, and “benevolence”. [1718] See Lisan al-`Arab by Ibn Manzur (8/208) and Taj al-`Arus by Zabidi (21/363).
Technically: It is an agreement for a commodity under guarantee, with performing the work set as a condition. Others said it is an agreement with craftsmen to produce something. [1719] See Bada’i` al-Sana’i` by Kasani (5/2) and Majallat al-Ahkam al-Adliyyah, p. 31 (entry no. 124). The elements of the contract of manufacturing are as follows:   1.      The Manufacturer (As-Sani'): This is the person responsible for preparing the raw materials and actively engaging in the work either personally or through delegated representatives.   2.      The Client (Al-Mustasni'): This is the one seeking the manufacturing service. The product resulting from the manufacturing process is called "Al-Masnou'" or the manufactured item.   3.      The Price (Ath-Thaman): This is the payment made by the person seeking the manufacturing service in exchange for the manufactured item.   See Majallat al-Ahkam al-Adliyyah, p. 31 (entry no. 124). For example, a manufacturer could agree a contract with the customer to manufacture a specific thing, such as building a dwelling, or manufacture some furniture for the home, such as the details for a sitting room.
2. Ruling on manufacturing
Manufacturing is permissible according to its conditions, [1720] In a manufacturing contract, it is required to state the kind, type, quantity, and required descriptions of the manufactured item, and to specify the term. and this was the position of the Hanafis, [1721] According to Hanafis, if the term (Ajal) is mentioned in the context of manufacturing, the contract transforms into a sale contract (Salam). In this case, the conditions of a Salam contract are considered applicable. Tabyin al-Haqa’iq by Zayla`i (4/123) and Al-Bahr al-Ra’iq by Ibn Nujaym (6/185). the basis for the decision of the Islamic Fiqh Academy, [1722] A decision was issued by the Islamic Fiqh Council approving the permissibility of the manufacturing contract. The text of the decision is as follows:   Decision No: 67/3/7   “The assembly of the Islamic Fiqh Academy, convened in its seventh session in Jeddah, Kingdom of Saudi Arabia, from 7-12 Dhu al-Qa`dah 1412 AH / 9-14 May 1992 CE., after reviewing the research submitted to the Academy on the topic of ‘the manufacturing contract’ and after listening to the discussions surrounding it and considering the objectives of Shariah in the interests of the servants and the jurisprudential rules of contracts and transactions, and recognizing that the manufacturing contract plays a significant role in promoting industry and opening wide avenues for Islamic finance and economic development, it has been decided:   1.      The manufacturing contract, which involves work and a specific product, is binding for both parties if its pillars and conditions are met.   2.      The following conditions are required in the manufacturing contract:   (a) Specification of the manufacturer's type, kind, quantity, and required characteristics. (b) Definition of the term.   3.      It is permissible in the manufacturing contract to delay the entire price or distribute it into known instalments for specified periods.   4.      The manufacturing contract may include a penalty clause according to what the parties agree upon unless there are compelling circumstances. Allah knows best.   Through the manufacturing contract, Islamic financial institutions can contribute to revitalizing industries, agriculture, and crafts in the Islamic market. Islamic banks, contracting with a client for construction, establishment of factories, or the supply of goods under Shariah-compliant conditions, may also enter into a parallel manufacturing contract with another contractor under the same conditions, executing the contract at a lower price. The profit for the Islamic bank would then be the difference between the two contracts, and Allah knows best.” and the preferred opinion of Ibn `Uthaymin, [1723] Ibn `Uthaymin was asked about a man who owns a furniture store. Sometimes, a buyer comes to him and requests the customization of a living room. The buyer needs to go to another city for this customisation, and then they agree on the price, and perhaps the down payment is received before going for customisation, and he responded: “Yes, there is nothing wrong with this because he did not sell a specific item to him. Instead, they agreed on the manufacturing of a specific item. The correct view is that there is nothing wrong with it, and there is no objection. This is binding on him, and he should fulfil the terms of the contract accordingly.” Liqa’ al-Bab al-Maftuh (no. 131). and a practical consensus was reported to that effect. [1724] Kasani said: “It is permissible and commendable, as there is consensus among people on this. They commonly engage in such practices without objection in various transactions.” Bada’i` al-Sana’i` (5/2). Zayla`i said: “As for manufacturing, there is a consensus established through continuous practice from the time of the Prophet g until today.” Tabyin al-Haqa’iq (4/123). Ibn Nujaym said: “Its evidence is consensus by action, and it is established to be a commendable action.” Al-Bahr al-Ra’iq (6/185).
Evidence:
(1) From the Book:
“They pleaded, ‘O Dhu al-Qarnayn! Surely Ya’juj and Ma’juj are spreading corruption throughout the land. Should we pay you tribute, provided that you build a wall between us and them?’ He responded, ‘What my Lord has provided for me is far better. But assist me with resources, and I will build a barrier between you and them.’” [1725] al-Kahf, 94-95.
Ibn `Abbas said that “a tribute (kharj)” means “a great reward”. [1726] See Fath al-Bari by Ibn Hajar (6/385).
Allah Exalted mentioned that they asked Dhu al-Qarnayn to build a barrier for them, offering to pay him for it from their own wealth. This is a manufacturing agreement, and the legislations established before us also apply to us so long as they are not abrogated. [1727] See the research on “the manufacturing contract” by Muhammad al-Ashqar, published in Buhuth Fiqhiyyah fi Qadaya Iqtisadiyyah Mu`asirah by Muhammad al-Ashqar and others, p. 228.
(2) From the Sunnah:
Nafi` said that `Abdullah ibn `Umar k narrated to him, “The Prophet g had a gold ring made for him, and he turned its gemstone towards the palm of his hand when he wore it…”, until the end of the hadith. [1728] Reported by Bukhari (5876) and Muslim (2091). The wording here is from Bukhari.
The Prophet “had a gold ring made (istana`a)”, meaning that he instructed for it to be crafted for him, similar to saying “iktataba” to mean that he instructed for something to be written. [1729] See Al-Nihayah fi Gharib al-Hadith wa al-Athar (3/56).
Sahl ibn Sa`d h narrated that the Prophet g sent a message to a woman from the Ansar saying: “Order your servant who is a carpenter to prepare some pieces of wood (i.e. a pulpit) for me so that I may sit upon them when I am speaking to the people.” [1730] Reported in full length by Bukhari (917). Also reported by Muslim (544). The wording here is from Bukhari.
(3) Because of the people’s regarding the possibility of this type of trade, because they have engaged in such agreements through the ages without objection. [1731] See Bada’i` al-Sana’i` by Kasani (5/2) and Tabyin al-Haqa’iq by Zayla`i (3/124).
(4) Because of necessity, as a person may need specific types of footwear crafted to particular specifications. Rarely can one find ready-made items that precisely match these requirements, necessitating the need for customization. If this were not permissible, people would face difficulties. [1732] See Bada’i` al-Sana’i` by Kasani (5/2).
(5) Because it involves the permissible combination of two contracts – a salam contract and a lease contract. Salam is a contract for the sale of goods under warranty, while the hiring of artisans necessitates their work. If a transaction combines the aspects of two valid contracts, it remains permissible. [1733] See Bada’i` al-Sana’i` by Kasani (5/2).
(6) Because even if the item is non-existent, it becomes associated with what exists due to the necessity, such as a Muslim in need of it. Therefore, it does not fall under the category of selling something that does not exist in absolute terms. [1734] See Bada’i` al-Sana’i` by Kasani (5/2).

Thirdly: The supply contract (`aqd al-tawrid)
1. Defining “the supply contract”
It is an agreement in which one party commits to deliver specified goods, deferred periodically over a specified timeframe, to another party in exchange for a predetermined amount which is either partly or fully deferred. [1735] See Majallah Majma` al-Fiqh al-Islami, issue 12, (2/571).
2. Ruling on the supply contract
The supply contract is permissible, regardless of whether the subject matter of the contract requires manufacturing or not. The commodity is described in the pledge and the supplier is obligated to deliver it at the specified time, and this was stated in the decision of the Islamic Fiqh Academy. [1736] The decision of the Islamic Fiqh Academy of the Organisation of Islamic Cooperation stated:   “In the twelfth session of the International Islamic Fiqh Council held in Riyadh, Saudi Arabia, from 25 Jumada al-Akhirah until the beginning of Rajab 1421 AH / 23-28 September 2000 CE, after reviewing the research submitted to the council regarding the topic of "Contracts of Supply and Tenders," and after listening to the discussions that took place among the members of the council, its experts, and some scholars, the following decisions were made:   Contract of Supply:   The contract of supply is an agreement in which one party commits to delivering specified goods periodically over a defined period to another party in exchange for an agreed-upon deferred amount, either in full or in part. If the subject of the supply contract requires manufacturing, then the contract is considered a manufacturing contract, and its rules apply.   If the subject of the supply contract is a non-manufactured good, and it is described in the contract that the supplier is obligated to deliver it at the agreed-upon time, the contract can be one of two types: a. The supplier accelerates the payment of the full amount at the time of the contract, and this would be considered a sale contract, subject to its legitimate conditions as explained in the decision of the Council number 85 (2/9). b. If the supplier does not accelerate the full payment at the time of the contract, this is not permissible because it is based on a binding agreement between the parties. The Council's decision number 40-41 states that a binding agreement is similar to the contract itself. If the agreed-upon date is not binding for either party, then it is permissible, and the sale can be completed with a new contract or through delivery.” Majallah Majma` al-Fiqh al-Islami, issue 12, (2/571-572). This is because if manufacturing is required, then it is a manufacturing contract, and if not, then it is a salam contract where the supplier either receives the full payment or a non-binding agreement if he receives part of the payment, and both are permissible. [1737] See Majallah Majma` al-Fiqh al-Islami, issue 12, (2/571-572).

Fourthly: The trade of absent commodities
1. The trade of absent commodities without any visual inspection or description to remove ambiguity
The trade of absent commodities without any visual inspection or description to remove ambiguity is permissible, and the buyer has the option to either keep or return the commodity upon seeing it. [1738] See the section on “the trade of an absent commodity”.
2. The trade of absent commodities with a description to remove ambiguity [1739] For example, through a catalogue.
The trade of absent commodities with a description to remove ambiguity is permissible. [1740] See the section on “the trade of an absent commodity”.