The Word has power- even the ordinary written word has a power. If it is an inspired word it has still more power. What kind of power or power for what depends on the nature of the inspiration and the theme and the part of the being it touches. If it is the Word itself, - as in certain utterances of the great Scriptures, Veda, Upanishads, Gita, it may well have a power to awaken a spiritual uplifting impulse, even certain kinds of realization. To say that it cannot contradicts spiritual experience.
The Vedic poets regarded their poetry as Mantras, they were the vehicles of their own realizations and could become vehicles of realization for others. Naturally, these mostly would be illuminations, not the settled and permanent realisation that is the goal of Yoga- but they could be steps on the way or at least lights on the way. I have had in former times many illuminations, even initial realizations while meditating on verses of the Upanishads or the Gita. Anything that carries the Word, the Light in it, spoken or written, can light this fire within, open a sky, as it were, bring the effective vision of which the Word is the body.
(Sri Aurobindo, ‘Sri Aurobindo on Himself and On The Mother’, Sri Aurobindo Ashram, Pondicherry 1953)