How should the comprehensive denial in «لَا رَيْبَ فِيهِ» be understood?

Departing from the Expected Form: Rhetorical Reclassification of the Addressee

• As denying any warranted ground for doubt about the Qur’an
• No human can ever experience doubt
• No word in the Qur’an can have meaning
• It is merely an interrogative expression