Vivekachudamani Slokas 364-366 :

In the following three Slokas Guru continues talking about Nirvikalpa Samadhi. In that state of meditation, Guru says that all the knots of residual impressions carried from past get dissolved (364). To highlight the importance of Nirvikalpa Samadhi, Guru talks about the relative merits of the various stages in a spiritual joutney, namely the stages of listening (Sravanam), Reflection (mananam), and meditation (Nidhi-dhyasa). Concludes that Nirvikalpa Samadhi is the best (365). Finally concludes saying that the true nature of the Brahman is clearly realized in the state of Nirvikalpa Samadhi only and no other way (366).
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Sloka 364:

समाधिनानेन समस्त वासना
ग्रन्थेर्विनाशे अखिल कर्म नाशनः।
अन्तर्बहिः सर्वत एव सर्वदा
स्वरूप विस्फूर्तिः अयत्नतः स्यात्॥364॥

1 समाधिनानेन समस्त वासना 
  ग्रन्थेर्विनाशे अखिल कर्म नाशनः।

अनेन समाधिना -
in this state of Yoga;
समस्त वासना ग्रन्थेः विनाशे -
with all the knots of all residual impressions destroyed
अखिल कर्म नाशनः -
all the actions come to an end;

3 अन्तर्बहिः सर्वत एव सर्वदा-
within and without , everywhere and always;

4 स्वरूप विस्फूर्तिः अयत्नतः स्यात् -
manifestation of one's universal natures takes place spontaneously

Sloka summary 364 :

In this state of Yoga (Nirvikalpa samadhi), with all the knots of residual impressions destroyed, all the actions are destroyed ; Manifestation of ones universal natures takes place spontaneously within and without , everywhere and always.

That with realization of Brahman, all the knots of all residual impressions destroyed, and all the actions come to an end, is also the Statement of Srutis. ( 'bhidyante hridaya granthih, kshiyante tasya karmabhih'- knot of the heart is broken and all his Karmas wane away')


Sloka 365

श्रुतेः शतगुणं विद्यात्
मननं मननादपि।
निधिध्यासं लक्षगुणम्
अनन्तम् निर्विकल्पम्॥ 365॥

श्रुतेः शतगुणं विद्यात् मननं-
Reflection(Manana) is hundred times better than listening (Sravana);

मननादपि निधिध्यासं लक्षगुणम्  ( विद्यात्)-
hundred thousand times better than Reflection(Manana) is meditation (Nidhidhyasa);

अनन्तम् निर्विकल्पम्  (विद्यात्)-
Nirvikalpa Samadhi is infinitely superior (to all);


Sloka summary 365:

Reflection(Manana) is hundred times better than listening (Sravana). Meditation (Nidhidhyasa) is  a hundred thousand times better than reflection (Manana);Nirvikalpa Samadhi is infinitely superior to all


Sravanam, Mananam, and Dhyanam are the classical stages in the progress of spiritual journey. Guru is highlighting that Nirvikalpa Samadhi is the ultimate stage that one should reach. In that state the true nature of Brahman becomes evident on its own. The residual impressions of the past karmas also get dissolved in that realization of Supreme Self.  


Sloka 366

निर्विकल्पक समाधिना स्फुटम्
ब्रह्मतत्त्वं अवगम्यते धृवम्।
नान्यथा चलतया मनोगतेः
प्रत्ययांतर विमिश्रितम् भवेत्॥

1 निर्विकल्पक समाधिना स्फुटम् -
Crystal clear in Nirvikalpa samadhi; 

2 ब्रह्मतत्त्वं अवगम्यते धृवम्-
True nature of Brahman is realized with certainty;

3a नान्यथा - न अन्यथा - no other way;

By Nivikalpa samadhi the true mature of Brahman is realized definitely with clarity. There is no other way 


For full realization of the nature of the Brahman, there is no way other than Nirvikalpa Samadhi, is the conclusion of the Guru. For in other paths the wavering mind will be locked to other variations of Brahman such as Saguna Brahman instead of Nirguna Brahman.

3b चलतया मनोगतेः -
with unsteadiness of  mind;

4 प्रत्ययांतर विमिश्रितम् भवेत्-
it is apt to become mixed with other perceptions

With unsteadiness of  mind, it is apt to become mixed with other perceptions.

Sloka summary 366:

By Nivikalpa samadhi the true mature of Brahman is realized definitely with clarity. There is no other way. With unsteadiness of  mind, it is apt to become mixed with other perceptions.

So to realize the true nature of Brahman Nirvikalpa Samadhi is a must.
How does one reach that state is an immediate question and Guru answers the same in following Slokas.

॥ओं तत् सत्॥



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