योगवासिष्ठः yogavāsiṣṭhaḥ - book-5, chapter-61, verse-18

ततो वर्षसहस्रेण तपसा दारुणात्मना ।
प्रापदभ्यासवशतो ज्ञानमात्मप्रसादजम् ॥ १८ ॥

tato varṣasahasreṇa tapasā dāruṇātmanā ,
prāpadabhyāsavaśato jñānamātmaprasādajam 18

18. tataḥ varṣasahasreṇa tapasā dāruṇātmanā
prāpat abhyāsavaśataḥ jñānam ātmaprasādajam

18. tataḥ varṣasahasreṇa dāruṇātmanā tapasā
abhyāsavaśataḥ ātmaprasādajam jñānam prāpat

18. Then, through a thousand years of severe ascetic discipline (tapas) and by the power of his spiritual practice, he attained knowledge born from the clarity and grace of his inner self (ātman).

Words meanings summery:

• ततः (tataḥ) - then, afterwards, thence

• वर्षसहस्रेण (varṣasahasreṇa) - by a thousand years

• तपसा (tapasā) - by asceticism, by penance

• दारुणात्मना (dāruṇātmanā) - qualifying the nature of the 'tapas' (ascetic discipline) (by a severe nature, by a fierce spirit)

• प्रापत् (prāpat) - he attained, he obtained

• अभ्यासवशतः (abhyāsavaśataḥ) - due to the power of practice, by dint of practice

• ज्ञानम् (jñānam) - knowledge, wisdom

• आत्मप्रसादजम् (ātmaprasādajam) - born of the serenity of the self, arising from self-grace

Words meanings and morphology

ततः (tataḥ) - then, afterwards, thence

(indeclinable)

वर्षसहस्रेण (varṣasahasreṇa) - by a thousand years

(noun)

Instrumental, neuter, singular of varṣasahasra

varṣasahasra - a thousand years

Compound type : dvigu (varṣa+sahasra)

• varṣa – year, rain
  noun (neuter)
  Root: vṛṣ (class 1)
• sahasra – a thousand
  noun (neuter)

तपसा (tapasā) - by asceticism, by penance

(noun)

Instrumental, neuter, singular of tapas

tapas - asceticism, penance, austerity

Root: tap (class 1)

दारुणात्मना (dāruṇātmanā) - qualifying the nature of the 'tapas' (ascetic discipline) (by a severe nature, by a fierce spirit)

(adjective)

Instrumental, neuter, singular of dāruṇātman

dāruṇātman - having a severe nature, fierce-spirited

karmadhāraya compound

Compound type : karmadhāraya (dāruṇa+ātman)

• dāruṇa – severe, harsh, terrible
  adjective (masculine)
  Root: dāru
• ātman – self, soul, spirit
  noun (masculine)
  Root: an (class 2)

Note: agrees with 'tapasā'

प्रापत् (prāpat) - he attained, he obtained

(verb)

3rd person , singular, active, past imperfect (laṅ) of prāp

verb root pra-āp

Prefix: pra

Root: āp (class 5)

अभ्यासवशतः (abhyāsavaśataḥ) - due to the power of practice, by dint of practice

(indeclinable)

ablative suffix -tas added to abhyāsavaśas

Compound type : tatpuruṣa (abhyāsa+vaśa)

• abhyāsa – practice, repetition, study
  noun (masculine)
  from abhi-as
  Prefix: abhi
  Root: as (class 4)
• vaśa – will, power, control, influence
  noun (masculine)
  Root: vaś (class 1)

Note: functions as an ablative of cause

ज्ञानम् (jñānam) - knowledge, wisdom

(noun)

Accusative, neuter, singular of jñāna

jñāna - knowledge, wisdom, understanding

from jñā

Root: jñā (class 9)

आत्मप्रसादजम् (ātmaprasādajam) - born of the serenity of the self, arising from self-grace

(adjective)

Accusative, neuter, singular of ātmaprasādaja

ātmaprasādaja - born of the serenity of the self (ātman), arising from inner clarity

tatpuruṣa compound ending in -ja (born from)

Compound type : tatpuruṣa (ātmaprasāda+ja)

• ātman – self, soul, spirit
  noun (masculine)
  Root: an (class 2)
• prasāda – clarity, serenity, grace, favor
  noun (masculine)
  from pra-sad
  Prefix: pra
  Root: sad (class 1)
• ja – born, produced from
  adjective (masculine)
  suffix -ja, from root jan
  Root: jan (class 4)

Note: agrees with 'jñānam'