683 – Ibn ʿUmar (may Allah be pleased with them both) reported: “The Messenger of Allah, peace and blessings be upon him, forbade najsh.” Agreed upon. (1)
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Glossary of the ḥadith:
– najsh (with an open nūn, a silent jīm, followed by an emphatic shīn): Linguistically it refers to flushing game out of its hiding place; one says, “najashtu the animal,” meaning, “I roused it.” Hence the nājish is the one who drives out the game.
 In the Sharīʿah it means: for someone who has no intention of buying the commodity to bid up its price—whether to benefit the seller, harm the buyer, pursue both aims, or simply out of mischief.

Points derived from the ḥadith:
1 – The report contains a prohibition of najsh: raising the price of an item on offer not to purchase it, but to burden the buyer with a higher price, secure a higher return for the seller, achieve both objectives, or merely for sport.
2 – The prohibition denotes impermissibility. Ibn Baṭṭāl said: the scholars unanimously agree that the nājish is sinful for his action.
3 – According to the well-known view in the school of Imām Aḥmad, the sale contract remains valid; however, if the buyer has been wronged by an unusually large surcharge caused by the nājish, he is entitled either to keep the item at the agreed price or to rescind the sale and reclaim his money.
4 – When the price increase is not exorbitant, al-Wazīr (Ibn Hubayra) said: the jurists concur that minor distortion in the price does not impair the validity of the sale.