Is purchasing a commodity in installments by paying its price to the bank with an increase considered usury or a usurious loan, or is it permissible financing?

If the seller sells the commodity by installments and agrees with the bank to pay the immediate price on behalf of the customers, so that the bank collects it from them with an usurious increase, then this is forbidden usury. The same applies if he sells the debt to the bank for less. However, if the bank acquires ownership of the commodity and then sells it to the buyer at an increased price, this is a valid and permissible sale.