«وَمَا تِلْكَ بِيَمِينِكَ يَا مُوسَىٰ»
And what is that in your right hand, O Moses?
This Qur’anic question (Ṭā Hā, 20:17) asks about something already known to God. Its interrogative wording does not imply any lack of divine knowledge. The form directs attention and prepares for what follows in the narrative.
The example shows that interrogative syntax and genuine need for information are not identical: an interrogative can serve other communicative purposes.