The Rules of Sale (Bayʿ) Conditions for a Valid Contract

Saying that « trade is permitted » (Qurʾān 2:275) does not mean that all commercial practices are. To guarantee justice and mutual consent (tarāḍin), Islamic jurisprudence has defined rigorous conditions for the validity of a sale (bayʿ).

Major works of fiqh, such as Ibn Qudāma’s Al-Mughnī (Ḥanbalī school) or al-Kāsānī’s Badāʾiʿ al-Ṣanāʾiʿ (Ḥanafī school), devote hundreds of pages to these rules. Here is a synthesis of the pillars of a valid contract.

The Pillar of Form: Offer and Acceptance (Ījāb and Qabūl)

An Islamic contract (ʿaqd) exists only through the meeting of a will to sell and a will to buy. This meeting is expressed by:

• Al-Ījāb (the offer): The first party’s expression of willingness to conclude the contract. (E.g.: « I sell this to you for €100 »).
• Al-Qabūl (acceptance): The second party’s agreement, which must match the offer exactly. (E.g.: « I accept »).

Modern fiqh precision: This formulation need not be verbal. Contemporary scholars accept clicking a « Buy » button (electronic sale) or simply placing an item on the checkout belt and paying (sale by conduct or muʿāṭāt) as valid forms of ījāb and qabūl, so long as custom (ʿurf) recognizes them.

Conditions Related to the Object of Sale (Al-Mabīʿ)

This is the heart of Islamic commercial regulation. The item sold must meet several strict conditions.

1. The object must be lawful in itself (Mubāḥ)

One cannot sell what Islam forbids to consume or use. The sale of alcohol, pork, drugs, or religious idols is radically void. A contract concerning an unlawful good is considered non-existent in Islamic law.

2. The object must exist at the time of sale

As a general rule, one cannot sell what does not yet exist (e.g. the fruit of a tree that has not yet blossomed). This rule avoids disputes arising from uncertainty. Legal exception: The salam or istiṣnāʿ contract, where the Prophet (sws) permitted the sale of a future manufactured or agricultural good under conditions of extremely precise description.

3. The seller must own it (Mulk)

This is one of the most important rules—and among the most violated in modern finance (notably short selling).

One may sell only what one truly owns and has physically (or constructively) received (qabḍ). This prevents speculation on nothing.

4. The object must be deliverable

Selling a bird in flight, an uncaught fish in the ocean, or a stolen car one is unsure of recovering renders the contract invalid. If the seller cannot guarantee delivery, it amounts to a form of gambling.

The Prohibition of Gharar (Excessive Uncertainty)

Gharar means « uncertainty », « deception », or « ambiguous risk ». The Prophet Muḥammad (sws) explicitly forbade « the sale involving gharar » (Reported by Muslim, from Abū Hurayra).

For a sale to be valid, there must be no ignorance (jahāla) regarding essential elements of the contract:

• The object must be known: Its nature, quantity, and quality must be specified. Selling « what is in this closed box » without describing it is gharar.
• The price must be known: The exact amount of the transaction must be fixed at the time of agreement.
• The term must be known: If payment is deferred, the exact date must be fixed.

Hidden Defects and the Right of Rescission (Khiyār)

Fiqh al-muʿāmalāt strongly protects the buyer. The seller has an absolute religious duty to disclose any defect (ʿayb) in the goods.

If the buyer discovers a defect that was hidden from him, Islam grants him khiyār al-ʿayb (the defect option): the legal right to cancel the sale and recover his money, or to accept the item with a proportional price reduction.

Passing by a pile of grain at the market, the Prophet (sws) plunged his hand in and found it wet (the seller had hidden wet wheat underneath). He then declared the famous maxim: « Whoever deceives us is not of us. » (Reported by Muslim).

Summary

1. A contract requires offer and acceptance (ījāb and qabūl), clear and matching.
2. The item sold must be lawful, owned by the seller, and deliverable. « Do not sell what you do not own. »
3. Price, quantity, quality, and deadlines must be known precisely to avoid excessive uncertainty (gharar).
4. Hiding a defect is a grave sin that gives the buyer the legal right to cancel the transaction.

These rules protect against speculation on nothing and exploitation. But one absolute red line remains to be drawn. The next article goes into the technical details of the most complex prohibition in Islamic law: the different types of ribā (usury).