The bank interest is a kind of Riba which is Prohibited in sharia. Allah said in the Qur’an:[… but Allah hath permitted trade and forbidden usury…](Al-Baqarah 2:275)
Therefore, any job that deals directly with bank interests such as writing its contracts, signing or witnessing on them or being instrumental in making it is prohibited and working in these jobs is impermissible except in the case of extreme necessity; as necessity overrides prohibition. Moreover, the necessity is assessed according to its extent and the ruling is annulled when the state of necessity changes.
However, other jobs that do not relate directly to Riba such as engineers, buildings and machines maintenance workers, guards, etc., are permissible for those who do not find any other jobs outside a bank till they find alternative lawful ones.
In his response to this issue, Dr. Rajab Abu Maleeh, a sharia consultant, stated:
“According to the resolutions of the juristic assemblies and the majority of contemporary jurists, commercial banks that give or take interest, through lending or borrowing funds, deal in fact with the prohibited usury (Riba). This is based also on the legal contract that governs the relationship between the bank and the depositor or the borrower, which is founded on giving or taking loans (i.e. the bank owes money to the depositor and the borrower owes money to the bank) and, thus, falls under the rulings of loans in the Islamic jurisprudence (Fiqh).
The Prophet (peace and blessings be upon him) cursed ‘the one who accepts usury, the one who pays it, the one who writes [the contract] and the two persons who stand witness to it.’ He (peace and blessings be upon him) said about them all, “They are all equal.” (Muslim) This means that they all share the same sin; just as when the Islamic law prohibits any matter, it blocks all ways that lead to it.
The one who works in such banks may perform one of the following two jobs:
1- Working in an assistant job, which has nothing to do with writing the contracts of usury or witnessing to them, for an institution that practices some lawful transactions such as bank transfers and banking services, and practices at the same time unlawful transactions such as giving or taking interest. In this case, it is permissible for those who cannot find other lawful jobs to work in places where the lawful and the unlawful are mixed, provided that they are not directly involved with the prohibited actions.
2- Working in writing and dealing with the contracts of usury. The one who does this is cursed according to the hadith, in which the Prophet (peace and blessings be upon him) cursed the one who accepts usury, the one who pays it, the one who writes the contract and both the witnesses. It is impermissible to do this job except in the case of extreme necessity; as necessity overrides prohibition.
Moreover, the necessity is assessed according to its extent and the ruling is annulled when the state of necessity changes.
There are some points and regulations for you to notice and anyone wants to work in these places or those who are already working there:
First: Livelihood and lifetime are determined and guaranteed by Allah; as He (Exalted and Glorified be He) says, “And in the heaven is your provision, and that which you are promised.” (Adh-Dhariyat51: 22)
The Prophet (peace and blessings be upon him) said, “The Holy Spirit revealed to me that that no soul shall die until it finishes its set provisions and term limit. Therefore, be pious, and strive for gains beautifully. Let not delayed gains push you to acquire such by disobeying Allah, for what Allah holds shall not be obtained save by obeying Him.” (Al-Hilyah)
Also, `Abdullah ibn Mas`ud (may Allah be pleased with him) said, “Allah’s Prophet, the true and truly inspired, told us, ‘(The matter of the Creation of) a human being is put together in the womb of the mother in forty days, and then he becomes a clot of thick blood for a similar period, and then a piece of flesh for a similar period. Then Allah sends an angel who is ordered to write four things. He is ordered to write down his (i.e. the new creature’s) deeds, his livelihood, his (date of) death, and whether he will be blessed or wretched (in religion). Then the soul is breathed into him. So, a man amongst you may do (good deeds till there is only a cubit between him and Paradise and then what has been written for him decides his behavior and he starts doing (evil) deeds characteristic of the people of the (Hell) Fire. And similarly a man amongst you may do (evil) deeds till there is only a cubit between him and the (Hell) Fire, and then what has been written for him decides his behavior, and he starts doing deeds characteristic of the people of Paradise.’” (Muslim)
In another narration according to Muslim, “When the drop of (semen) remains in the womb for forty or forty-five nights, the angel comes and says: My Lord, will he be wretched or fortunate? And both these things would be written. Then the angel says: My Lord, would he be male or female? And both these things are written. And his deeds and actions, his death, his livelihood; these are also recorded. Then his document of destiny is rolled and there is no addition to and subtraction from it.?” (Muslim)
Second: Whoever leaves something for the Sake of Almighty Allah, He (Exalted and Glorified be He) recompenses him with something even better than what he left. Let not the much money deceives you; as the permanent little is better than the discontinuous much. Always remember that every body which is nourished with that which is unlawful will be first in the Hell-fire.”