المعنى الاصطلاحي :

A sale in which a seller sells a commodity to the buyer provided that when the buyer returns the commodity the seller should return the money.

الشرح المختصر :

"Bay‘ al-amānah" (trust-based sale) is a sale conducted on the mutual trust and confidence between the contracting parties, namely the seller and the buyer. This trust is sometimes required on part of the buyer and on part of the seller at other times. If it is required on part of the buyer, it is called "bay‘ al-wafā’" (repurchase-option sale) because the buyer holds a fiduciary obligation to carry out the terms of the trust to keep the subject-matter of sale (item/property/asset/commodity) in his possession until the beneficiary returns the payment and takes the purchased item back. If the trust is required on part of the seller, who is obliged to be honest about the price of the object of sale and the purchase, and the sale is done at the original cost with no increase or decrease, it is called "bay‘ at-tawliyah" (sale at the price of purchase). If the seller is selling only part of the object of sale in return for part of its price, it is called "bay‘ al-ishrāk" (partnership-based sale). If the two contracting parties agree to trade at a price equal to the original cost plus a specific mark-up, it is called "murābahah" (sale with profit), and if the sale price is lower than the original cost (i.e. trading takes place at a marked-down price), it is called "bay‘ al-wadee‘ah" (sale in which the subject matter is exchanged at a discount from its original price, i.e. selling at a specific loss); it is also called "bay‘ al-hateetah" or "bay‘ an-naqeesah". If the two contracting parties agree to trade at a price equal to the original cost, it is called "bay‘ al-mustarsil" (sale to the unaware of the price). In contrast to "bay‘ul-amānah" (trust-based sale), there is "bay‘ al-musāwamah" (bargain sale), which is defined as a sale contract without disclosure of the cost price and profit margin. Hence, the price is determined by bargaining without reference to the item's cost to the seller.