Verse 1

In plain words

In the eighth chapter, we were taught the disciplined practice of concentration through the body's subtle channel, directed toward Brahman as possessing attributes. And its fruit — reaching Brahman itself, in due course, by the ascending path that begins with fire and light — was described as a state from which one never returns. But someone might now wonder: is this really the only way to reach liberation, and no other? To dispel exactly that worry, the Blessed Lord now speaks —

This knowledge of Brahman — the part still to be spoken, and the part already spoken in the earlier chapters —

Holding that teaching in view, Krishna says 'this.' The word 'but' is there to single out exactly what he means, decisively. And what he means is: this alone — right knowledge — is the direct means to liberation, nothing indirect about it. That is what the scriptures and tradition themselves say: 'Vāsudeva is everything' (Bhagavad Gītā 7.19), 'this whole world truly is the Self' (Chāndogya Upaniṣad 7.25.2), 'one alone, without a second' (Chāndogya Upaniṣad 6.2.1), and passages like these; nothing else will do. And the scriptures say this too: 'those who understand it any other way live under something other than themselves, and their worlds simply run out' (Chāndogya Upaniṣad 7.25.2). This is what I will tell you — the most secret thing there is, the most closely guarded — because you, Arjuna, hold no envy in your heart. What is it? Knowledge. What kind of knowledge? Knowledge that comes with real, lived realization, not mere theory — knowing this, having reached it, you will be freed from everything harmful, from the very bondage of this cycle of birth and death.

Close to the Sanskrit

In the eighth chapter, the qualified discipline of concentration by way of the subtle channel has been taught. And its fruit — namely attainment of Brahman, in due course of time, through the sequence beginning with fire and radiance — has been indicated as taking the form of non-return. There, lest one think 'only by this very method is the fruit of attaining liberation obtained, and not otherwise' — with the desire to dispel this apprehension, the Blessed Lord said —

This knowledge of Brahman, which is to be spoken and which has been spoken in the earlier chapters,

Having brought that teaching present in mind, he says 'this.' The word 'tu' serves the purpose of a specific determination. This alone, right knowledge, is the direct means of attaining liberation — from scriptural and traditional texts such as 'Vāsudeva is all' (Bhagavad Gītā 7.19), 'this whole is verily the Self' (Chāndogya Upaniṣad 7.25.2), 'one only, without a second' (Chāndogya Upaniṣad 6.2.1), and so on; not anything else — and also from scriptural texts such as 'but those who know it otherwise, ruled by another, theirs are perishable worlds' (Chāndogya Upaniṣad 7.25.2), and so on. That, to you, the most secret, the most concealed, I shall declare, tell, to one free from envy, devoid of malice. What is that? Knowledge. Of what kind? Accompanied by direct realization, joined with experience — knowing which, having attained which, you shall be released from evil, from the bondage of transmigratory existence.

In plain words

To this the Paramātma replied, “Arjuna, listen! All that you have named are indeed kinds of knowledge, each needed at its own time, but through them no one can get away from the bonds of worldly existence. That by knowing which men can be freed from the bondage of saṃsāra, which takes the form of birth and death — that alone is ‘Anubhava Jñāna’. Only those who have such Anubhava Jñāna get away from the bonds of worldly existence and can become seekers of Mokṣa.”

“Hearing the knowledge of the śāstras through ācāryas is of some help, but they cannot show the true form. Whoever, together with Anubhava Jñāna, and free of envy, comes to know the tattva of the Ātma, the supreme secret — he alone can be called a ‘complete jñāni’.”