What is the ruling on purchasing an apartment through an Islamic bank that charges a large profit, and is this permissible with the intention of securing shelter and housing, and not for trading, especially since the questioner owns another house in his home country that requires maintenance and is not registered in the husband’s name?

It is permissible to deal with an Islamic bank and purchase an apartment through it using an installment sale or istisna' (manufacturing contract) system, provided that the bank owns the apartment before selling it and it enters into its guarantee, and that the bank adheres to the Shariah guidelines in all its transactions. However, if the bank is usurious or does not adhere to the Shariah guidelines, it is not permissible to deal with it, nor is it permissible to purchase the apartment except in accordance with the Shariah guidelines.