Chinmayananda's romanization word-by-word:
amātraś-caturtho-‘vyavahāryaḥ prapañcopaśamaḥ śivo-‘dvaita evam-oṅkāra ātmaiva saṁviśaty-ātmanātmānaṁ ya evaṁ veda.
Amātraś: the partless;
Caturtho: fourth (turīya);
Vyavahāryaḥ: beyond empirical transactions;
Prapañcopaśamaḥ: free from universe;
Śivo-‘dvaita: auspicious non-dual;
Evam-oṅkāra: thus Oṅkāra;
Ātmaiva: Self alone;
Saṁviśaty: enters, merges;
Ātmanātmānaṁ: through (his own) self into (his own supreme) Self;
Ya evaṁ veda: that thus who knows.
Translations:
That which has no parts, the soundless, the cessation of all phenomena, all blissful and non-dual Aum, is the fourth, and verily it is the same as the Ᾱtman. He, who knows this, merges his self in the supreme Self, the individual in the total.
~Chinmayananda
The Fourth (Turiya) is without parts and without relationship; It is the cessation of phenomena; It is all good and non-dual. This Aum is verily Atman. He who knows this merges his self in Atman—yea, he who knows this.
~Nikhilananda
Turīya is the Silence, which is beyond transactions, free from the world, auspicious, and non-dual. Thus Oṅkāra is the very ātmā. One who knows thus enters the ātmā by himself.
~Paramarthananda
The Self is the Silence beyond transactions, free from the world, auspicious and non-dual. Thus Omkara is the very Self. One who knows this enters the Self by the Self.
~Swartz
That which has no part the partless Om; becomes but the Fourth, Turiya, merely the absolute Self; which is beyond empirical relations, because of the disappearance of names and nameables, that are but forms of speech and mind; the culmination of phenomenal existence; the auspicious; and non-dual. thus; Om, as possessed of the three letters and as applied by it man with the above knowledge, verily identical with the Self possessed of three quarters. he who knows thus; enters; into his own Self; through his own self. The knower of Brahman, who has realized the highest Truth, has entered into the Self by burning away the third state of latency; and hence he is not born again, since Turiya has no latency (of creation).
~Shankara (tr-Gambhirananda)
Commentaries:
When we talk about the equation of silence and Turīyaṃ, the word silence has a special connotation. It is not the conventional silence. Silence here has a special meaning. The conventional silence, absence of sound, should not be taken as Turīyaṃ.
This should not be equated to Turīyaṃ for two reasons. The first reason is that the conventional silence is taken to mean a mere absence of sound or noise and thus it is a negative entity. Absence is not a positive entity. If this negative description is applied to Turīyaṃ, one will end up with the Buddhist śūnyavāda teaching that the ultimate truth is emptiness.
The second reason is that the conventional silence is experienced only when the sound has disappeared. In the arrival of sound, conventional silence goes away and vice-versa. Conventional silence is a relative entity subject to arrival and departure. Comparison with conventional silence will make Turīyaṃ a relative entity.
Thus amātrā, Silence should not be taken as the relative silence. When you experience silence externally, it is the absence of sound and when thoughts and disturbances are absent in the mind, you experience internal silence, blankness. When you experience internal silence and there is internal blankness, is there only blankness?
Other than that blankness, there is something else, because of which you are aware of the blankness. If the silence is experienced and known by me, it means that there is a knowing consciousness principle that pervades the silence.
~Paramarthananda
In this way the mind “merges into” witness consciousness. If reality is non-dual, the “merger” is like the merger of water into water, not the merger of salt into water, meaning liberation is the removal of ignorance of one’s identity, not the gaining of a new identity or the dissolution of an existent identity. A jiva cannot “dissolve” into consciousness, because it is not real in the first place and there is no experiential access to consciousness, insofar as it is non-dual. It cannot exist as something else, because the existence it enjoys is existence itself.
~Swartz
Just as in the previous mantras we have been given promises of the benefits which the meditator would gain through such meditations on Aum, here also the Guru informs the disciple that on meditating regularly upon the silent aspect of Aum, the individual self, meaning the egoistic idea of separativeness in us, gets merged into the divine experience of the all-soul, the eternal and the immortal.
~Chinmayananda
Those who know Brahman, those who realise the Highest Reality merge into Self, because in their case the notion of the cause which corresponds to the third quarter (of Atman) is destroyed (burnt). They are not born again, because Turlya is not a cause. For, the illusory snake which has merged in the rope on the discrimination of the snake from the rope, does not reappear as before, to those who know the distinction between them, by any effort of the mind (due to the previous impressions).
~Shankara (tr-Nikhilananda)
It may be contended that like a man coming back to the realm of duality having experienced deep sleep, the knower of Self who has identified himself with Turiva may also come back to the illusory universe, for Prajna and Turiya are identical having a common feature of the perception of non-duality. This contention is without ground, because Turiya is not a cause.. Hence it cannot give rise to the world of illusory experience. Unlike Prajna it is beyond all relations of cause and effect. Therefore one who has identified himself with Turiya can never see the illusion of the manifold.
~Nikhilananda commenting on above
