Bhagavan Sri Ramana composed Ulladu Narpadu – Reality in Forty Verses – which is regarded even by ‘traditional’ advaitins as having the status of an upanishad. Lakshmana Sarma received direct instruction from Sri Ramana on this work, and thereafter wrote a detailed commentary on it, which even Bhagavan commended to others.

v.10 of UN: In the phenomenal world knowledge is never unaccompanied by ignorance; neither is ignorance ever divorced from knowledge. True knowledge is the Awareness of the original Self – as it truly is – the source of the ego-self which is the origin of all, by the start of the quest “to whom is the ignorance and knowledge of the world of objects”?

v.29: Without mouthing aloud ‘I’, but diving deep into the Heart and seeking the place from where the consciousness as ‘I’ rises, is the direct path of winning the Awareness of the real Self. But the mere contemplation “This body I am not; That Brahman AM I”, no doubt is helpful as an auxiliary tool to that direct path, but can that, by itself be the direct means, namely to the quest of the Self?

From LS’ commentary:

“Nidhidhyasana is the ceaseless contemplation of the content of that statement [‘I am indeed that Brahman’]. The akandakara vritti that blossoms out of this contemplation wipes out the nescience in all its entirety and jnana or Knowledge, it is believed, then shines in all its glory and effulgence. This type of sadhana is but a mental practice involving the triad of the meditator, the object of meditation and meditation. The intent and purpose of the quest [self-investigation / self-enquiry] is to make the mind that is awake, achieve quiescence . . . The main objective of vicara is the annihilation of the mind, which can never be accomplished by this contemplation.”

As an aside, compare and contrast with the comments of the 35th Sankaracharya of Sringeri on nirvikalpa samadhi:
“The mind is so extremely pure at that time that it cannot be discerned distinctly from Brahman. The mind is then like a pure crystal. The effulgent Atman manifests in it clearly… After the realisation becomes stable, the mind is destroyed and one becomes a jivanmukta”

v.32: While the Upanishadic statements that preach the principle of Atman hail loud and clear “THAT THOU ART’, an aspirant, not getting established as ‘That’ by seeking the truth of the Self through the quest, meditating instead ‘That Brahman am I and not this body’, is due to want of strength of mind. Does not that Content Beyond reside as the Self within, ever and anon?

From LS’ commentary:

“In the stark thoughtlessness marked by the extirpation of the ego he should abide as the residual form that survives as the Self, called Brahman. Therefore the true significance of the deliberation of the principle of Atman contained in this mahavakya is to abide as the Self by the quest of the Self, and the Upanishadic utterance therefore is not an injunction to contemplate on the teaching”

What Bhagavan says – that ceaseless investigation into oneself / one’s ego is the means to ‘go beyond’ and results in ‘no-mind’ or dissolution of the ego – is not at all different from Nisargadatta, Krishnamurti and I think, Vasistha (but Ramesam is better qualified to comment on this than I). They all say you have to do this yourself; no guru or upanishad or path can do it for you; they can only point in the direction: that what you seek is what you already are, and is beyond concepts.

Therefore Knowledge / jnana is not a concept in the mind (however deep the conviction) that “I am Brahman, and not the ego”, though clearly helpful as a start.  It is the absence of any separate I-thought, such that only Pure Consciousness / Knowledge IS.