What is the requirement for non-Muslims when administering the legal oath?

Primary text

The oath by Allah Almighty is required for both the Muslim and the non-Muslim alike; no one is permitted to swear by anything other than Allah. This is established by the Divine statement, 'Then they both shall swear by Allah' (Quran 5:106), and by the Prophetic saying, 'Whoever is to swear, let him swear by Allah or remain silent.' Thus, the oath must invoke Allah, irrespective of the person's faith.