Is it obligatory for an employee in a usurious bank to leave his job if he has no other source of income and supports his family, or should he continue his work and search for an alternative?

Working in usurious banks is not permissible, because a worker there is either directly involved in usury or assisting in it, and the one who assists is a partner in sin. This is based on the saying of the Prophet, peace and blessings be upon him: "The Messenger of Allah, peace and blessings be upon him, cursed the one who consumes usury, the one who pays it, its scribe, and its two witnesses, and he said: 'They are all equal [in sin].'" However, working in such banks is permissible out of necessity for someone who cannot find a permissible job to earn his livelihood and the livelihood of those he supports, provided that he diligently searches for another job. If he finds one, he must leave his job at the bank, because what is permitted due to necessity is estimated by its measure. The basis for this is the Almighty's saying: "And He has already explained to you what He has forbidden to you, except for that to which you are compelled," and His saying, exalted be He: "But whoever is compelled, neither desiring [it] nor transgressing [its limit], there is no sin upon him. Indeed, Allah is Forgiving and Merciful."