Is the monthly amount paid by the bank for freezing a sum of money in a current account considered usury, and how can the husband be convinced of that?

First: The husband must review the beliefs of the Alawi sect and reject whatever among them contradicts Islam, believing instead in what the Book of Allah and the Sunnah (definition) of His Prophet indicate.

Second: Freezing an account in the bank in exchange for an additional sum is precisely usury (riba), because it is a loan with interest, and every loan that draws a benefit is usury. It is not a condition for usury that the borrower be in need. Allah has threatened those who consume usury with war and the wiping out of blessings. The Prophet, peace and blessings be upon him, cursed the consumer of usury, its payer, its scribe, and its two witnesses. Usurious money has no blessing in it and brings worry and sorrow to its owner. A Muslim must be content with what is lawful and satisfied with it.