What is the ruling of Sharia on the transaction of purchasing a house from a company that builds residential homes, where the buyer paid an upfront sum, and the remaining amount is paid monthly over a long period, and then it became clear to him that there is a third party, which is a savings bank, in the contract, bearing in mind that the buyer is ignorant of Sharia transactions and has paid a large sum that cannot be refunded if the contract is rescinded?

Upon reviewing the attached contract, it became clear that it is an explicit usurious contract that is impermissible to deal with. The bank lends the buyer an amount in exchange for usurious interest, and scholars have unanimously agreed that every loan that draws a benefit is Riba (usury). If the buyer is unable to annul the contract, or if annulling it would result in the loss of what they have paid, then it appears permissible for them to continue with the transaction. This is because, even though the usurious loan is forbidden, it confers ownership according to the preponderant opinion. However, anyone who intends to enter into a suspicious transaction must consult people of knowledge before doing so.