What is the ruling on buying an apartment in installments from a usurious bank through Murabaha, whereby the bank authorizes you to purchase the apartment, then sells it to you with an agreed-upon profit margin and in interest-free installments, with the apartment mortgaged to the bank, or if the bank already owns the apartments and the sale is conducted in the same manner?

There is no legal impediment in Islamic law to purchasing an apartment owned by a bank through Murabaha, provided its conditions are met. Among these conditions is that the buyer's promise should not be binding on him to purchase. If the commitment is binding, the Murabaha becomes invalid. If the agent purchases what he was instructed to buy, the principal is obligated either to fulfill his promise or to compensate the agent for the damages incurred. A binding promise is religiously binding on the promiser, unless there is a valid excuse, and legally binding if it is contingent on a cause and the promisee incurred a cost. The obligation would be either to fulfill the promise or to compensate. If purchasing is not the only option, then there is no objection to this transaction, although it is preferable to avoid it unless necessary.