Are loans offered by Islamic banks—whereby the bank pays the price of a commodity specified by the client and takes a 20% commission on it, then the remainder is paid in installments—considered usury? And what is the legitimate alternative for young people who wish to start projects or get married?

Borrowing from usurious banks is forbidden. However, engaging in a genuine Murabaha transaction with an Islamic bank is permissible, and it is a lawful alternative to interest-based borrowing. If the Murabaha is not conducted in accordance with Islamic law, that does not justify borrowing with interest. A Muslim must fear Allah, be patient, and strive to find permissible alternatives.