What is the ruling on Barwa Bank's new "Thara'a" savings account, which offers monthly profits and cash prizes (QAR 5,0, 25,0, 50,0, and 1 million), in addition to other benefits?

Depositing money into a savings account for investment by an Islamic bank in exchange for a percentage of the profits is considered a Mudarabah contract, and its rulings apply to it. It is permissible for the bank to offer prizes to investment account holders, provided that this does not lead to guaranteeing the capital of the Mudarabah, or part of it, and that these prizes are paid from the bank's own funds and not from the profits of the investment accounts.