The same ruling that applies to “selling over a sale” applies equally to “buying over a purchase,” for both situations share the very same rationale, and because in juristic usage a purchase is itself called a sale.

The scholars also disagreed over the validity of a town-dweller’s selling on behalf of a Bedouin (bayʿ al-ḥāḍir lil-bādī).

According to the well-known position in Imām Aḥmad’s school, the sale is void provided four conditions are all met:

1. People are in need of the commodity in question.
2. The Bedouin has come to town intending to sell his goods at the going market price of that day.
3. He is unaware of that market price.
4. The town-dweller approaches him with the purpose of selling the goods for him.

If any one of these conditions is absent, the sale stands valid. Their proof is that a prohibition entails invalidity.

The majority, however, deem the sale valid yet sinful, for it contravenes a prophetic prohibition.

The majority of scholars—including the three Imams, Mālik, al-Shāfiʿī, and Aḥmad—hold that when a taṣrīyah animal is returned to the seller, the buyer must return one ṣāʿ of dates to compensate for the milk, exactly as stated in the sound hadith.

The Ḥanafīs maintain that nothing is to be returned; rather, the milk is the buyer’s in exchange for the fodder he provided. They sought to rebut the clear text of the hadith by claiming it was abrogated by the verse, “But if you retaliate, then retaliate with the like of that with which you were afflicted” (Q 16:126).

Even if we were to assume that the verse was revealed after the hadith, it offers no proof here, for it speaks of retribution in the realm of punishments, a subject wholly unrelated to ours.

Their second objection is that the hadith conflicts with analogical reasoning: “Milk is a fungible good, so liability should be for its like and in proportion to its quantity, whereas the hadith fixes a single ṣāʿ regardless of whether the milk was little or much.”

Such objections—and others like them—have been fully answered by the scholars. It suffices to reply that an authenticated report from the Lawgiver takes precedence over qiyās, for it is itself an independent proof that must be heeded. Indeed, the very principles of jurisprudence rest upon textual proofs from the Lawgiver; without them no principles could be established. Hence, we cannot abandon a clear, sound hadith in favor of an unweighted analogy. Al-Khaṭṭābī says in Maʿālim al-Sunan: “Once a hadith is proven to be from the Messenger of Allah ﷺ, acting upon it becomes obligatory and it is, in itself, a foundational proof. The principles became principles only because the Sharia came with them, and the hadith of the taṣrīyah has reached us through reliable channels; therefore upholding it is incumbent, and forsaking it in favor of other principles is no more warranted than forsaking those principles for it.”