योगवासिष्ठः yogavāsiṣṭhaḥ - book-7, chapter-154, verse-18

अभ्यासाद्बोधविश्रान्तौ गुरुशास्त्रैकसेवनात् ।
द्वैताद्वैतदृशोः शान्त्या निर्वाणं चित्तमुच्यते ॥ १८ ॥

abhyāsādbodhaviśrāntau guruśāstraikasevanāt ,
dvaitādvaitadṛśoḥ śāntyā nirvāṇaṃ cittamucyate 18

18. abhyāsāt bodhaviśrāntau guruśāstraikasevanāt
dvaitādvaitadṛśoḥ śāntyā nirvāṇaṃ cittam ucyate

18. abhyāsāt bodhaviśrāntau guruśāstraikasevanāt
dvaitādvaitadṛśoḥ śāntyā cittam nirvāṇaṃ ucyate

18. When the mind rests in knowledge, through consistent practice and single-minded devotion to the guru and scriptures, and by the cessation of the perspectives of both duality and non-duality, it is then called liberation (nirvāṇa).

Words meanings summery:

• अभ्यासात् (abhyāsāt) - from practice, through consistent practice

• बोधविश्रान्तौ (bodhaviśrāntau) - in the resting in knowledge, in the repose of enlightenment

• गुरुशास्त्रैकसेवनात् (guruśāstraikasevanāt) - from the sole service/devotion to guru and scriptures

• द्वैताद्वैतदृशोः (dvaitādvaitadṛśoḥ) - of the perceptions/views of duality and non-duality

• शान्त्या (śāntyā) - by the cessation, through peace, by the calming

• निर्वाणं (nirvāṇaṁ) - liberation (nirvāṇa), extinguishment, ultimate freedom

• चित्तम् (cittam) - the mind, consciousness

• उच्यते (ucyate) - is called, is said, is declared

Words meanings and morphology

अभ्यासात् (abhyāsāt) - from practice, through consistent practice

(noun)

Ablative, masculine, singular of abhyāsa

abhyāsa - practice, repetition, study, exercise

action noun

From abhi-as (to throw, repeat)

Prefix: abhi

Root: as (class 4)

बोधविश्रान्तौ (bodhaviśrāntau) - in the resting in knowledge, in the repose of enlightenment

(noun)

Locative, feminine, singular of bodhaviśrānti

bodhaviśrānti - resting in knowledge/enlightenment, repose in understanding

Compound type : tatpurusha (bodha+viśrānti)

• bodha – knowledge, understanding, enlightenment
  noun (masculine)
  action noun
  From root budh
  Root: budh (class 1)
• viśrānti – rest, repose, cessation, tranquility
  noun (feminine)
  action noun
  From vi-śram (to rest)
  Prefix: vi
  Root: śram (class 4)

गुरुशास्त्रैकसेवनात् (guruśāstraikasevanāt) - from the sole service/devotion to guru and scriptures

(noun)

Ablative, neuter, singular of guruśāstraikasevana

guruśāstraikasevana - singular service/devotion to guru and scriptures

Compound type : tatpurusha (guru+śāstra+eka+sevana)

• guru – teacher, preceptor, spiritual guide
  noun (masculine)
• śāstra – scripture, sacred text, treatise, science
  noun (neuter)
  Root: śās (class 2)
• eka – one, sole, singular, unique
  numeral (masculine)
• sevana – serving, attending, devotion, practice
  noun (neuter)
  action noun
  From root sev
  Root: sev (class 1)

द्वैताद्वैतदृशोः (dvaitādvaitadṛśoḥ) - of the perceptions/views of duality and non-duality

(noun)

Genitive, feminine, dual of dvaitādvaitadṛś

dvaitādvaitadṛś - the view of duality and non-duality

Compound type : tatpurusha (dvaita+advaita+dṛś)

• dvaita – duality, dualism
  noun (neuter)
• advaita – non-duality, non-dualism
  noun (neuter)
  Negation of dvaita
  Prefix: a
• dṛś – seeing, eye, view, perception
  noun (feminine)
  action noun / root noun
  Root: dṛś (class 1)

शान्त्या (śāntyā) - by the cessation, through peace, by the calming

(noun)

Instrumental, feminine, singular of śānti

śānti - peace, tranquility, cessation, calming, quietude

action noun

From root śam

Root: śam (class 1)

निर्वाणं (nirvāṇaṁ) - liberation (nirvāṇa), extinguishment, ultimate freedom

(noun)

Nominative, neuter, singular of nirvāṇa

nirvāṇa - extinguishment, liberation, ultimate freedom from suffering and rebirth (saṃsāra)

action noun / PPP

From nir-vā (to blow out, extinguish)

Prefix: nis

Root: vā (class 2)

चित्तम् (cittam) - the mind, consciousness

(noun)

Nominative, neuter, singular of citta

citta - mind, consciousness, thought, intellect

From root cit

Root: cit (class 1)

उच्यते (ucyate) - is called, is said, is declared

(verb)

3rd person , singular, passive, present (lat) of vac

Root: vac (class 2)