The expression “tajāhul” can literally suggest acting ignorant. In discussing divine speech, some rhetoricians therefore favor the more neutral phrase “presenting the known as though unknown.”
The actual point is that an interrogative form can serve a wise purpose despite complete knowledge of its answer. It does not attribute deficient knowledge to the speaker.
The name of a literary figure should not be confused with a literal psychological claim about the speaker. In scripture, the rhetorical purpose must be identified without alleging ignorance.