A question regarding the sale of a truck mortgaged to the bank, where its owner agreed with his relative that he would give him a sum to buy a taxi in exchange for the relative using the truck currently, provided that its ownership would transfer to him after the bank loan is repaid within eight years, knowing that the amount paid is less than the truck's real value. The question is concerning the permissibility of this sale.

All praise is due to Allah, and may peace and blessings be upon the Messenger of Allah, his family, and companions. To proceed:

This transaction is impermissible for two reasons: 1. Lending money on the condition of loaning the truck is considered a loan that draws a benefit, which is forbidden, because every loan that draws a benefit is usury (riba). 2. Stipulating the sale of the truck within the loan is considered a condition of a contract within a contract, which is also forbidden.

Furthermore, if the vehicle is mortgaged to the bank or if the bank prohibits its sale, then it is not permissible to sell it except with the bank's permission.

And Allah knows best.