योगवासिष्ठः yogavāsiṣṭhaḥ - book-6, chapter-101, verse-52

अथ चेतसि तत्त्वज्ञ स्पन्दास्पन्दौ त्वमेकताम् ।
नीत्वा तिष्ठ यथाकाममैक्यमागत्य शाश्वतम् ॥ ५२ ॥

atha cetasi tattvajña spandāspandau tvamekatām ,
nītvā tiṣṭha yathākāmamaikyamāgatya śāśvatam 52

52. atha cetasi tattvajña spandāspandau tvam ekatām |
nītvā tiṣṭha yathākāmam aikyam āgatya śāśvatam ||

52. atha tattvajña,
tvam cetasi spandāspandau ekatām nītvā,
śāśvatam aikyam āgatya,
yathākāmam tiṣṭha.

52. Therefore, O knower of truth, having brought both agitation and non-agitation in your mind to a state of oneness, and having attained eternal unity (aikyam), remain as you wish.

Words meanings summery:

• अथ (atha) - now, then, therefore, moreover

• चेतसि (cetasi) - in the mind, in consciousness

• तत्त्वज्ञ (tattvajña) - O knower of truth, O expert in reality

• स्पन्दास्पन्दौ (spandāspandau) - agitation and non-agitation, vibration and non-vibration

• त्वम् (tvam) - you

• एकताम् (ekatām) - oneness, unity, sameness

• नीत्वा (nītvā) - having led, having brought, having carried

• तिष्ठ (tiṣṭha) - remain, stand, stay

• यथाकामम् (yathākāmam) - as one wishes, according to desire, voluntarily

• ऐक्यम् (aikyam) - unity, oneness, identity

• आगत्य (āgatya) - having come, having attained, having approached

• शाश्वतम् (śāśvatam) - eternal, perpetual, everlasting, constant

Words meanings and morphology

अथ (atha) - now, then, therefore, moreover

(indeclinable)

चेतसि (cetasi) - in the mind, in consciousness

(noun)

Locative, neuter, singular of cetas

cetas - mind, consciousness, intellect

तत्त्वज्ञ (tattvajña) - O knower of truth, O expert in reality

(adjective)

Vocative, masculine, singular of tattvajña

tattvajña - knower of truth, expert in reality

Compound type : tatpuruṣa (tattva+jña)

• tattva – truth, reality, principle, essence
  noun (neuter)
• jña – knower, understanding
  adjective (masculine)
  From root ज्ञ (jñā)
  Root: jñā (class 9)

Note: Used here as a vocative proper noun or honorific.

स्पन्दास्पन्दौ (spandāspandau) - agitation and non-agitation, vibration and non-vibration

(noun)

Accusative, masculine, dual of spandāspanda

spandāspanda - agitation and non-agitation, vibration and non-vibration

Compound type : dvandva (spanda+aspanda)

• spanda – agitation, vibration, throbbing
  noun (masculine)
  From root स्पन्द् (spand)
  Root: spand (class 1)
• aspanda – non-agitation, stillness, absence of vibration
  noun (masculine)
  Negation of spanda (a + spanda)

त्वम् (tvam) - you

(pronoun)

Nominative, singular of yuṣmad

yuṣmad - you

एकताम् (ekatām) - oneness, unity, sameness

(noun)

Accusative, feminine, singular of ekatā

ekatā - oneness, unity, sameness

From eka + tā (abstract suffix)

नीत्वा (nītvā) - having led, having brought, having carried

(indeclinable)

Absolutive (Gerund)

Formed from the root नी (nī) with the suffix क्त्वा (ktvā)

Root: nī (class 1)

तिष्ठ (tiṣṭha) - remain, stand, stay

(verb)

2nd person , singular, active, imperative (loṭ) of sthā

Imperative Mood, 2nd Person Singular

Root: sthā (class 1)

यथाकामम् (yathākāmam) - as one wishes, according to desire, voluntarily

(indeclinable)

Compound type : avyayībhāva (yathā+kāma)

• yathā – as, according to
  indeclinable
• kāma – desire, wish, love
  noun (masculine)
  Root: kam (class 1)

ऐक्यम् (aikyam) - unity, oneness, identity

(noun)

Accusative, neuter, singular of aikya

aikya - unity, oneness, identity

From eka (one) with suffix -ya

आगत्य (āgatya) - having come, having attained, having approached

(indeclinable)

Absolutive (Gerund)

Formed from the root गम् (gam) with prefix आ (ā) and suffix ल्यप् (lyap)

Prefix: ā

Root: gam (class 1)

शाश्वतम् (śāśvatam) - eternal, perpetual, everlasting, constant

(adjective)

Accusative, neuter, singular of śāśvata

śāśvata - eternal, perpetual, everlasting, constant

Note: Agrees with 'aikyam'.