invalidity; hence they pronounced corrupt the sale carried out by najsh (bidding up the price without intent to buy), the sale concluded over one’s brother’s sale, and the sale of goods whose defects have been concealed. The correct view is that the prohibition in such cases was not enacted as a pure right of Allah but to protect the rights of human beings.

Scholarly disagreement:

• The majority of jurists maintain that a purchase made by someone who intercepts a caravan is nonetheless valid, based on hadith 686 and because the prohibition does not touch the contract itself—neither its essence nor its conditions—but was issued only to prevent harm to the caravan traders.

• They disagreed, however, about whether the seller retains the right of rescission once he reaches the marketplace. Al-Shafiʿi and Ahmad held that he does retain this option whenever the loss he has suffered exceeds the customary margin, citing hadith 686 and arguing that the injury has already occurred and cannot be redressed except through this option. Abū Ḥanīfah denied any such option; the first opinion is the stronger.

• The scholars also differed over the validity of a sale concluded over another person’s sale—or a purchase over his purchase. Ahmad and the Ẓāhirīs ruled both transactions invalid, reasoning that a prohibition entails invalidity. The other three schools considered the sale valid, since the prohibition does not relate to the contract itself but to an external matter.

• They further disputed the validity of a townsman’s selling on behalf of a desert-dweller. The well-known position of Ahmad’s school is that the transaction is void whenever four conditions are met:

1. People are in need of the commodity.
2. The seller has arrived intending to dispose of his goods at that day’s going price.
3. He is unaware of the current market price.
4. The townsman approaches him with the purpose of selling the goods for him.
   Their proof is that a prohibition entails invalidity.

• The majority of jurists, however, deem the sale valid, though sinful, because it contravenes the prophetic prohibition.