What is the ruling when the buyer and seller dispute the exact subject matter of a sale contract?
Chapter on Selling the Musarrah (Animal with milk retained in udder)
Al-Mughni
Book of Sales
Primary text
When a dispute arises regarding the specific item sold, such as the seller claiming to have sold a male slave ('Abd) and the buyer claiming to have purchased a female slave ('Jariyah), the testimony of each party is accepted concerning the item they deny receiving, provided they take an oath to support their denial. This is because each party asserts a contract concerning an item that the opposing party denies. Therefore, the statement of the denier is accepted.
Supporting text
If the seller swears that he did not sell the female slave, then the female slave remains in the seller's possession, or if the buyer had taken possession, it is returned to the seller. If the male slave remains in the seller's possession, it stays with him, and the buyer has no claim to it since he denies purchasing it. However, the seller must return the price to the buyer because the agreed-upon item (the male slave) was not delivered to the buyer. If the male slave is in the buyer's possession, the buyer must return it to the seller, as the buyer did not deny purchasing it. If the seller has returned the price to the buyer, the seller cannot demand its return. If the seller has not received the price, the seller has the right to rescind the sale and reclaim the item, analogous to the situation where the buyer becomes bankrupt.