Thus, in these days Guru Ramana, who shines as the form of the one Self-knowledge (ekatmajnana-swarupa), has made clear in this verse, Ekatma Vivekam, sung by Him what the truth of that oneness of Self is, destroying (thereby) the 'I am the body'- feeling (dehatma-bhava) of His devotees.
ॐ
The only thing (vastu) that exists eternally by its own light is that one Self. When in those (ancient) days the Adi-Guru (the primal Guru, Sri Dakshinamurti) revealed that vastu through speechless speech, say, who can reveal it through speech?
— Ekatma Vivekam - The Knowledge of the Oneness of Self, Verse 5
Note:
Eternal, unchanging, self-existing and selfshining—such is the definition of reality given by Sri Bhagavan.
"What is the standard of reality? That alone is real which exists by itself, which reveals itself by itself and which is eternal and unchanging",
says Sri Bhagavan in Maharshi’s Gospel, Book Two, chapter 3 (*). According to this definition, Self is the sole reality, for it alone exists and shines eternally, by its own light, without change and without dependence upon any other thing. All else—the mind, body, world and so on—are unreal, for they are transitory and subject to change, and they exist and shine not by their own light but only by depending upon the light of the one Self.
When in ancient days even Sri Dakshinamurti —the Adi Guru, Guru of all Gurus—was able to reveal the truth of that one Self only through Silence, the speechless speech, who else can reveal it through speech?
In this connection, Sri Bhagavan once told the following story to Sri Muruganar:
When the four aged Sanakadi Rishis first saw the sixteen-year-old Sri Dakshinamurti sitting under the banyan tree, they were at once attracted by Him, understanding Him to be the real Sadguru. They approached Him, did three pradakshinas around Him, prostrated before Him, sat at His Feet and began to ask very shrewd and pertinent questions about the nature of reality and the means of attaining it. Because of the great compassion and fatherly love (vatsalya) which He felt for His aged disciples, the young Sri Dakshinamurti was overjoyed to see their earnestness, wisdom, and maturity, and hence He gave apt replies to each of their questions. But as He answered each consecutive question, further doubts rose in their minds and they asked further apt questions. Thus they continued to question Sri Dakshinamurti for one whole year, and He continued to clear their doubts through His compassionate answers. Finally, however, Sri Dakshinamurti understood that if He gave more answers to their questions more doubts would rise in their minds and hence there would never be an end to their ignorance (ajnana). Therefore, suppressing even the feeling of compassion and fatherly love which was welling up within Him, He merged Himself into the supreme Silence. Because of their great maturity (which had been ripened to perfection through their yearlong association with the Sadguru), as soon as Sri Dakshinamurti thus merged Himself, they too were automatically merged within into Silence, the state of Self.
Wonder-struck on hearing Sri Bhagavan narrating the story in this manner, Sri Muruganar remarked that in no book is it mentioned that Sri Dakshinamurti ever spoke anything. "But this is what actually happened", replied Sri Bhagavan. From the authoritative way in which Sri Bhagavan thus replied and from the clear and descriptive way in which He had told the story, Sri Muruganar understood that Sri Bhagavan was none but Sri Dakshinamurti Himself.
Why is it that even Sri Dakshinamurti was unable to reveal the truth of the oneness of Self through speech? Because, from the one Self, the supreme Silence, rises the ego on account of weakness or slackness in Self-attention, from the ego then rise thoughts on account of further weakness in Self-attention, and from thoughts finally rises speech on account of still further weakness. Therefore, how can speech, which is the great-grandson of Silence and which is born only through weakness, be capable of describing or revealing the nature of Self, its original source?
Moreover, since Self alone truly exists and since there is nothing that exists as other than Self, who is there to reveal Self and to whom is it to be revealed? Speech is possible only in a state of duality and otherness, and since duality and otherness do not exist in the state of Self, it is beyond the range of speech. Therefore. Self can be realized only in the state of Silence, in which it is clearly known that nothing else—neither speech, thoughts nor the ego —has ever truly existed. This knowledge is ajata, the absolute truth, the truth of the oneness of Self.
In The Mountain Path Vol.19, Nº I, January 1982 (pdf)
(*) 2002 edition, page 67: https://selfdefinition.org/ramana/Maharshi's-Gospel.pdf