Source
Taken from: Fatāwā Amunpuri by Shaykh Ghulām Muṣṭafā Ẓahīr Amunpuri
Question
What is the ruling on taking an oath from someone at the time of appointing them to a job?
Answer
Taking an oath from an employee appointed to a government or private position is permissible. However, if this oath is violated, no expiation (kaffārah) is required. Nevertheless, the person does become sinful, because such an oath is essentially a promise and a contract, and violating a contract is a major sin.
Evidence from the Qur’an
❀ Allah Almighty says:
﴿وَأَوْفُوا بِالْعَهْدِ إِنَّ الْعَهْدَ كَانَ كَانَ مَسْئُولًا﴾
[Banī Isrā’īl: 34]
“Fulfill the covenant; indeed, the covenant will be questioned about.”