Najash and commercial deception

The najash (fictitious bid)

Najash is raising the price of goods offered for sale without wanting to buy, to deceive others into bidding, or praising the goods falsely, including by the seller himself. The scholars agree it is forbidden: "do not practice najash" (al-Bukhari 2043, Muslim 1515; al-Bukhari 6562, Muslim 1516).

Is the sale concluded over such a bid valid? Hanafis, Shafi'is and the Hanbali madhhab hold it valid and binding, the sin resting on the najish, the prohibition protecting the buyer's right, repaired by an option or a price reduction. The Malikis and one Hanbali view void the sale, giving precedence to the right of Allah in the prohibition. As for the buyer's remedy: the Hanafis and the soundest Shafi'i view give him no option, the deception bearing on the price and not on the good; contrary to the soundest view, the Shafi'is grant the option when the seller abetted the bid; the Malikis grant the informed buyer the choice between keeping the good at the paid price and returning it at the day's value, the najash being treated as a defect; the Hanbalis grant the option in case of real overcharge.

The neighboring tricks

• Collusion to stop bidding: agreeing among buyers to stop raising the price so as to share the goods cheaply. Malikis and Ibn Taymiyya allow asking one person to refrain (the field of bidding stays open), and forbid the collusion of several: the seller keeps the choice between confirming and cancelling, and if the goods perish he takes the greater of price and value; such collusion deserves a deterrent punishment.
• Bidding over another's agreed price: offering more on a price already agreed between seller and buyer, before the conclusion: forbidden ("let none of you sell over the sale of his brother", al-Bukhari 2043, Muslim 1515).
• The broker sharing in the purchase: a broker in charge of the seller's call who partners with a bidder without the seller's knowledge betrays his trust: he is the one buying in reality (Ibn Taymiyya).

The protection of the villager

The same chapter forbids the townsman acting for the villager: the point is protecting the townspeople, as Ibn Rushd explains, or sparing the villager's ignorance of prices (Ibn Qudamah): "leave people, Allah provides for some of them through others" (Muslim 1522). Mere advice is debated: Malik disliked revealing prices to him; the Hanbalis allow advising without selling for him, following Talha's gesture toward the Bedouin.

Practical note

Auctions and marketplaces live on transparency: any artificial move on the price (fake bidder, colluding ring, biased broker) is the same fraud the Prophet condemned.