योगवासिष्ठः yogavāsiṣṭhaḥ - book-6, chapter-99, verse-14

असंकल्पनमात्रेण सम्यग्ज्ञानोदयात्मना ।
संकल्पः क्षीयते सिद्ध्यै स्वयमेवासदात्मकः ॥ १४ ॥

asaṃkalpanamātreṇa samyagjñānodayātmanā ,
saṃkalpaḥ kṣīyate siddhyai svayamevāsadātmakaḥ 14

14. asaṅkalpanamātreṇa samyagjñānodayātmanā
saṅkalpaḥ kṣīyate siddhyai svayam eva asadātmakaḥ

14. samyagjñānodayātmanā asaṅkalpanamātreṇa
asadātmakaḥ saṅkalpaḥ svayam eva siddhyai kṣīyate

14. When right knowledge (jñāna) arises, simply through the cessation of mental conception (saṅkalpa), that very mental conception (saṅkalpa)—which is unreal by its intrinsic nature (ātman)—is spontaneously destroyed, leading to perfection.

Words meanings summery:

• असङ्कल्पनमात्रेण (asaṅkalpanamātreṇa) - merely by the absence of mental conception; simply by non-volition

• सम्यग्ज्ञानोदयात्मना (samyagjñānodayātmanā) - by the intrinsic nature of the arising of right knowledge; through the self of the dawn of perfect wisdom

• सङ्कल्पः (saṅkalpaḥ) - mental conception; ideation; volition; intention

• क्षीयते (kṣīyate) - is destroyed; wastes away; perishes; is diminished

• सिद्ध्यै (siddhyai) - for the sake of spiritual perfection/liberation (for accomplishment; for perfection; for success; for attainment)

• स्वयम् (svayam) - oneself; by oneself; spontaneously; naturally

• एव (eva) - indeed; only; just; even

• असदात्मकः (asadātmakaḥ) - whose nature is unreal; having an unreal intrinsic nature

Words meanings and morphology

असङ्कल्पनमात्रेण (asaṅkalpanamātreṇa) - merely by the absence of mental conception; simply by non-volition

(noun)

Instrumental, neuter, singular of asaṅkalpanamātra

asaṅkalpanamātra - merely the absence of ideation/volition; only non-volition

Compound type : tatpuruṣa (a+saṅkalpana+mātra)

• a – not, non, un-
  indeclinable
• saṅkalpana – mental conception, ideation, volition, determination
  noun (neuter)
  verbal noun
  derived from saṃ-kḷp (to imagine, resolve) with suffix -ana
  Prefix: sam
  Root: kḷp (class 1)
• mātra – only, merely, size, measure
  adjective (neuter)

सम्यग्ज्ञानोदयात्मना (samyagjñānodayātmanā) - by the intrinsic nature of the arising of right knowledge; through the self of the dawn of perfect wisdom

(noun)

Instrumental, masculine, singular of samyagjñānodayātman

samyagjñānodayātman - the intrinsic nature of the arising of right knowledge

Compound type : tatpuruṣa (samyak+jñāna+udaya+ātman)

• samyak – right, proper, true, complete
  adjective
• jñāna – knowledge, wisdom, understanding
  noun (neuter)
  from root jñā (to know)
  Root: jñā (class 9)
• udaya – rising, appearance, dawn, origin
  noun (masculine)
  verbal noun
  from ud-i (to rise)
  Prefix: ud
  Root: i (class 2)
• ātman – self, soul, spirit, intrinsic nature
  noun (masculine)

Note: `ātman` in `ātmanā` declines as instrumental singular.

सङ्कल्पः (saṅkalpaḥ) - mental conception; ideation; volition; intention

(noun)

Nominative, masculine, singular of saṅkalpa

saṅkalpa - mental conception, ideation, volition, determination, intention

from saṃ-kḷp (to resolve, imagine)

Prefix: sam

Root: kḷp (class 1)

क्षीयते (kṣīyate) - is destroyed; wastes away; perishes; is diminished

(verb)

3rd person , singular, passive, present (laṭ) of kṣī

passive voice

from root kṣi (to destroy, perish), 9th class, passive form.

Root: kṣi (class 9)

Note: The root kṣi (9P) means "to destroy". The form kṣīyate (passive) means "is destroyed/perishes".

सिद्ध्यै (siddhyai) - for the sake of spiritual perfection/liberation (for accomplishment; for perfection; for success; for attainment)

(noun)

Dative, feminine, singular of siddhi

siddhi - accomplishment, success, perfection, attainment, supernatural power, liberation

from root sidh (to accomplish)

Root: sidh (class 4)

स्वयम् (svayam) - oneself; by oneself; spontaneously; naturally

(indeclinable)

एव (eva) - indeed; only; just; even

(indeclinable)

असदात्मकः (asadātmakaḥ) - whose nature is unreal; having an unreal intrinsic nature

(adjective)

Nominative, masculine, singular of asadātmaka

asadātmaka - having an unreal intrinsic nature; whose nature is non-existent

Compound type : bahuvrīhi (a+sat+ātman)

• a – not, non, un-
  indeclinable
• sat – real, existent, true, good
  adjective
  present active participle
  present participle of 'as' (to be)
  Root: as (class 2)
• ātman – self, soul, spirit, intrinsic nature
  noun (masculine)

Note: Qualifies 'saṅkalpaḥ'.