योगवासिष्ठः yogavāsiṣṭhaḥ - book-3, chapter-110, verse-4

सदेव हि महादुःखमसत्तां नयति क्षणात् ।
निष्कलङ्का मनोवृत्तिरन्धकारमिवार्करुक् ॥ ४ ॥

sadeva hi mahāduḥkhamasattāṃ nayati kṣaṇāt ,
niṣkalaṅkā manovṛttirandhakāramivārkaruk 4

4. sat eva hi mahāduḥkham asattām nayati kṣaṇāt |
niṣkalaṅkā manovṛttiḥ andhakāram iva arkaruk ||

4. hi,
niṣkalaṅkā manovṛttiḥ sat eva mahāduḥkham kṣaṇāt asattām nayati,
arkaruk andhakāram iva.

4. Indeed, a stainless mental activity (manovṛtti) instantly brings great suffering (duḥkha), which seems to be real, to a state of non-existence, just as the sun's radiance (arkaruk) [dispels] darkness (andhakāra).

Words meanings summery:

• सत् (sat) - that which appears to be real or existent (existent, real, good, true)

• एव (eva) - indeed, even (indeed, certainly, only, just)

• हि (hi) - indeed, surely (indeed, surely, because, for)

• महादुःखम् (mahāduḥkham) - great suffering (duḥkha) (great suffering, intense misery)

• असत्ताम् (asattām) - a state of non-existence (non-existence, unreality, non-being)

• नयति (nayati) - brings (to a state of) (leads, carries, brings, guides)

• क्षणात् (kṣaṇāt) - instantly, in a moment (from a moment, in an instant)

• निष्कलङ्का (niṣkalaṅkā) - pure, stainless (spotless, stainless, pure, faultless)

• मनोवृत्तिः (manovṛttiḥ) - a mental modification (manovṛtti) (mental activity, mind's modification, thought)

• अन्धकारम् (andhakāram) - darkness

• इव (iva) - just as (like, as, as if)

• अर्करुक् (arkaruk) - the sun's radiance (sun's radiance, sunlight)

Words meanings and morphology

सत् (sat) - that which appears to be real or existent (existent, real, good, true)

(adjective)

Accusative, neuter, singular of sat

sat - existent, real, true, good; being, reality

Present active participle

From √as (to be)

Root: as (class 2)

एव (eva) - indeed, even (indeed, certainly, only, just)

(indeclinable)

हि (hi) - indeed, surely (indeed, surely, because, for)

(indeclinable)

महादुःखम् (mahāduḥkham) - great suffering (duḥkha) (great suffering, intense misery)

(noun)

Accusative, neuter, singular of mahāduḥkha

mahāduḥkha - great suffering, intense misery

Compound of 'mahā' and 'duḥkha'.

Compound type : Karmadhāraya (mahā+duḥkha)

• mahā – great, large, mighty
  adjective
• duḥkha – suffering, misery, pain
  noun (neuter)

असत्ताम् (asattām) - a state of non-existence (non-existence, unreality, non-being)

(noun)

Accusative, feminine, singular of asattā

asattā - non-existence, unreality, non-being

From 'asat' + 'tā' (abstract noun suffix)

Note: Destination of 'nayati'.

नयति (nayati) - brings (to a state of) (leads, carries, brings, guides)

(verb)

3rd person , singular, active, present (laṭ) of nī

Present active indicative

Class 1, nayati

Root: nī (class 1)

Note: Subject is 'manovṛttiḥ'.

क्षणात् (kṣaṇāt) - instantly, in a moment (from a moment, in an instant)

(indeclinable)

Ablative singular used adverbially.

Root: kṣaṇ

निष्कलङ्का (niṣkalaṅkā) - pure, stainless (spotless, stainless, pure, faultless)

(adjective)

Nominative, feminine, singular of niṣkalaṅka

niṣkalaṅka - spotless, stainless, pure, faultless, blameless

Compound of 'nis-' (without) + 'kalaṅka' (stain, blemish).

Compound type : Bahuvrīhi (nis+kalaṅka)

• nis – out, forth, without, negation
  indeclinable
  prefix
• kalaṅka – spot, stain, blemish, fault
  noun (masculine)

मनोवृत्तिः (manovṛttiḥ) - a mental modification (manovṛtti) (mental activity, mind's modification, thought)

(noun)

Nominative, feminine, singular of manovṛtti

manovṛtti - mental activity, modification of the mind, thought, state of mind

Compound of 'manas' and 'vṛtti'.

Compound type : Tatpuruṣa (manas+vṛtti)

• manas – mind, intellect, thought
  noun (neuter)
  Root: man (class 4)
• vṛtti – activity, modification, state, mode of being
  noun (feminine)
  Root: vṛt (class 1)

अन्धकारम् (andhakāram) - darkness

(noun)

Accusative, masculine, singular of andhakāra

andhakāra - darkness, gloom

Compound of 'andha' (blind) and 'kāra' (maker/cause).

Compound type : Tatpuruṣa (andha+kāra)

• andha – blind
  adjective
• kāra – making, causing, doer, hand
  noun (masculine)
  From √kṛ (to do, make)
  Root: kṛ (class 8)

इव (iva) - just as (like, as, as if)

(indeclinable)

अर्करुक् (arkaruk) - the sun's radiance (sun's radiance, sunlight)

(noun)

Nominative, feminine, singular of arkaruc

arkaruc - sun's radiance, sunlight, splendor of the sun

Compound of 'arka' (sun) and 'ruc' (light, splendor).

Compound type : Tatpuruṣa (arka+ruc)

• arka – sun, ray, crystal
  noun (masculine)
  Root: arc (class 1)
• ruc – light, splendor, luster, beauty
  noun (feminine)
  Root: ruc (class 1)

Note: Subject of implied verb in the simile.