المعنى الاصطلاحي

Sale with the condition that whenever the seller pays back the money, the buyer must return the purchased item.

الشرح المختصر

"Bay‘-uth-thunya" (sale with exception/return sale) is one of the forbidden types of sale, and it is included under transactions that involve both sale and condition. In this sale transaction, the buyer and the seller agree while concluding the contract that the seller has the right to take the item back whenever he returns the money that he received from the buyer. This term is specific to the Māliki school of Fiqh. The Hanafi school calls it "bay‘ al-wafā’" and "bay‘ al-mu‘āmalah". The Hanbali school calls it "bay‘ al-amānah", because the item is like an "amānah" (trust) in the hands of the buyer. The Shāfi‘i school calls it "bay‘ al-‘uhdah", "bay‘ jā’iz", and "bay‘-ut-tā‘ah".