Buying and Selling: Buying and Selling Without a Formula

Practical Laws of Islam as per the teachings of Ayatullah Sistani

Ruling 2108

If at the time of the transaction the formula is not said but the seller, in exchange for the property that he takes from the buyer, makes the buyer the owner of his own property, the transaction is valid and both become owners [of the exchanged items].

-Ayatullah Sistani, Practical Laws of Islam, Buying and Selling