Points derived from the hadith:

1. The hadith shows that when a dispute arises between seller and buyer and neither side possesses proof, the seller’s statement is accepted—provided he swears an oath. The legal maxim is: whoever’s statement is accepted must back it with an oath.

2. This ruling is in line with the report narrated by al-Bayhaqī—parts of which are found in the two Ṣaḥīḥs—on the authority of Anas, that the Prophet ﷺ said: “The proof is upon the claimant, and the oath is upon the one who denies.” Commenting on that hadith, our teacher ʿAbd al-Raḥmān al-Saʿdī (may Allah have mercy on him) outlined the following scenarios involving disputes between buyer and seller; what follows is a concise summary:

   1. If they disagree about the amount of the price and neither has evidence, they both swear oaths. The procedure is that the seller swears, “I did not sell it for such-and-such; rather, I sold it for such-and-such,” then the buyer swears, “I did not buy it for such-and-such; rather, I bought it for such-and-such.” After that, each of them may annul the sale.
   2. If they differ over the form of payment, the currency customarily used in the locality is adopted, provided it matches the claim of one of them.
   3. If they dispute about the very item sold or its quantity, they both swear oaths and the contract is rescinded.
   4. If they disagree about a stipulated condition, a pledge, or a guarantor, the word of the one who denies its existence is accepted, for the default is that it does not exist.
   5. If one party claims the contract is void while the other maintains it is sound, the presumption is that the contract is valid; therefore, the word of the one affirming its validity is accepted, and the burden of proof lies upon the one alleging invalidity.
   6. If the sale was concluded on the basis of a description or a prior inspection, and the buyer then claims that the item’s condition has changed while the seller denies it, the buyer’s statement is accepted, because the original presumption is that the price is not yet binding upon him.
   7. If they differ about when a defect arose and both possibilities are plausible, the stronger opinion is that the seller’s statement is accepted, and this is the practice that people follow in dealings.