This is a remarkable description which we can find only in Savitri and not in other prose works of Sri Aurobindo, for instance in The Life Divine or The Synthesis of Yoga where the presentation is essentially for the enlightened intuitive reason. There is a certain degree of informality available in the letters Sri Aurobindo wrote to his disciples and one can see in them that he is quite free from professional constraints which otherwise he has to observe in formal writings. But everywhere there is the tightness in the line of argument, if these are to be considered as arguments.
In that sense in Savitri alone the occult comes out with its full luminous contents and force, with its unplumbable profundity, gold reaching yet deeper layers of gold, in Savitri where Sri Aurobindo the Yogi has complete freedom of expression, has no boundary conditions to be observed, where no horizons cut his view, where he can be, so to say, himself, absolutely himself. The Story of Creation narrated by him in Savitri belongs unmistakably to that category. In The Life Divine he had taken a position, in The Synthesis of Yoga he had taken a position; but in Savitri it is all unimpeded revelation, in it he had poured himself out in God’s great glory itself. So, I get puzzled when very knowledgeable people say that Savitri is The Life Divine in a verse form!
And yet there can be an essay in poetry, with its convincing logopoeia supported by image and music. The following description of the cosmic past and the future that awaits this creation is a wonderful example of the expository art carried out with utmost care and attention. Savitri is told by a deathless and mighty Voice to remember why she had taken the mortal birth and that she should get ready to house the divine Force in her soul in order to conquer Death. She has been initiated into Yoga and the review of the entire cosmic past is the first occult-spiritual experience she gets. The mystic-numinous origins of the shadowy beginnings are first disclosed to her: (pp. 477-86)