Swami Chinmayananda writes in the introduction to his commentary upon the Ashtavakra Gita of how in a way it is superior to the Upanishads, Brahma Sutras and Bhagavad Gita (these are the Prasthana Traya or ‘Holy Trinity’ of scriptures in Advaita Vedanta) in communicating the nature of the Supreme Reality.
Note the final paragraph in which all concepts, including that of ‘Supreme Reality’ or ‘Brahman’ are also dissolved:
In communicating to the seekers the unsurpassing beauty and indefinable perfections of the Absolute, the Upanisads stammer; the Brahma sutras exhaust itself and the Bhagavat Gita hesitates with an excusable shyness. A theme, in dealing with which, even these mighty books of Hinduism are thus, at best, unsatisfactory; we must, in sheer gratitude, admire Astavakra Samhita for the brilliant success it has achieved in communicating, through words, perhaps, more clearly the nature and glory of the Supreme Reality, than by the Prasthana Traya.
The student of this Samhita is himself giving the autobio-data of the liberated in life. We have here in this book a revealing autobiography of the Saint, the Liberated-in-life in King Janaka.
Beyond all assertions and denial, beyond the concepts of bondage and liberation, lies this Realm of the Self, wherein there is neither the individual-ego(jiva), nor is there even the Supreme-Reality (Brahman)!
The above was written by Swami Chinmayananda, taken from his introduction to the Ashtavakra Gita