योगवासिष्ठः yogavāsiṣṭhaḥ - book-5, chapter-12, verse-4

अनारतविवेकेन तेन सद्यः सनातनम् ।
पुनः कलङ्कं नैवाप्तमम्बरेणेव राजसम् ॥ ४ ॥

anāratavivekena tena sadyaḥ sanātanam ,
punaḥ kalaṅkaṃ naivāptamambareṇeva rājasam 4

4. anāratavivekena tena sadyaḥ sanātanam punaḥ
kalaṅkam na eva āptam ambareṇa iva rājasam

4. tena anāratavivekena sadyaḥ sanātanam (ātma-tattvam)
punaḥ rājasam kalaṅkam ambareṇa iva na eva āptam

4. Through his unceasing discrimination (viveka), that eternal (nature of the Self) immediately did not again acquire any blemish of rajas (rājasam), just as the sky remains untouched by impurities.

Words meanings summery:

• अनारतविवेकेन (anāratavivekena) - by unceasing discrimination, by continuous discernment

• तेन (tena) - by him, by that

• सद्यः (sadyaḥ) - immediately, at once, instantly

• सनातनम् (sanātanam) - the eternal Self or truth (implied) (eternal, ancient, everlasting, primeval)

• पुनः (punaḥ) - again, anew, furthermore

• कलङ्कम् (kalaṅkam) - blemish, stain, impurity, fault

• न (na) - not

• एव (eva) - indeed, certainly, only

• आप्तम् (āptam) - obtained, reached, acquired

• अम्बरेण (ambareṇa) - by the sky, by the atmosphere

• इव (iva) - like, as, as if

• राजसम् (rājasam) - (blemish) arising from rajas (rājasam) (pertaining to rajas, passionate, active, worldly)

Words meanings and morphology

अनारतविवेकेन (anāratavivekena) - by unceasing discrimination, by continuous discernment

(noun)

Instrumental, masculine, singular of anārataviveka

anārataviveka - uninterrupted discrimination, continuous discernment

Compound type : tatpuruṣa (anārata+viveka)

• anārata – uninterrupted, continuous, incessant
  adjective (masculine)
  Past Passive Participle
  From a-√ram (not ceasing), prefixed with 'na'
  Prefixes: na+ā
  Root: ram (class 1)
• viveka – discrimination, discernment, judgment, distinguishing
  noun (masculine)
  From vi-√vic (to separate, distinguish)
  Prefix: vi
  Root: vic (class 7)

तेन (tena) - by him, by that

(pronoun)

Instrumental, masculine, singular of tad

tad - that, he, she, it

Note: Refers to the king/individual

सद्यः (sadyaḥ) - immediately, at once, instantly

(indeclinable)

सनातनम् (sanātanam) - the eternal Self or truth (implied) (eternal, ancient, everlasting, primeval)

(adjective)

Nominative, neuter, singular of sanātana

sanātana - eternal, ancient, everlasting, perpetual, primeval

From sadā + tana (suffix indicating time)

पुनः (punaḥ) - again, anew, furthermore

(indeclinable)

कलङ्कम् (kalaṅkam) - blemish, stain, impurity, fault

(noun)

Accusative, masculine, singular of kalaṅka

kalaṅka - spot, stain, blemish, impurity, defect

न (na) - not

(indeclinable)

एव (eva) - indeed, certainly, only

(indeclinable)

Note: Emphatic particle, here intensifies the negation 'na'

आप्तम् (āptam) - obtained, reached, acquired

(adjective)

Nominative, neuter, singular of āpta

āpta - obtained, reached, acquired, trustworthy

Past Passive Participle

From ā-√āp (to obtain, reach)

Prefix: ā

Root: āp (class 5)

Note: In a passive construction 'kalaṅkam ... na eva āptam' (blemish was not obtained)

अम्बरेण (ambareṇa) - by the sky, by the atmosphere

(noun)

Instrumental, neuter, singular of ambara

ambara - sky, atmosphere, clothing

Note: Used in the simile 'like by the sky'

इव (iva) - like, as, as if

(indeclinable)

राजसम् (rājasam) - (blemish) arising from rajas (rājasam) (pertaining to rajas, passionate, active, worldly)

(adjective)

Accusative, neuter, singular of rājasa

rājasa - relating to rajas, passionate, active, worldly, dusty

From rajas + -a (taddhita suffix)