योगवासिष्ठः yogavāsiṣṭhaḥ - book-3, chapter-81, verse-84

यत्र नास्ति द्वितीयो हि तत्रैकस्यैकता कथम् ।
एकतायामसिद्धायां द्वयमेव न विद्यते ॥ ८४ ॥

yatra nāsti dvitīyo hi tatraikasyaikatā katham ,
ekatāyāmasiddhāyāṃ dvayameva na vidyate 84

84. yatra na asti dvitīyaḥ hi tatra ekasya ekatā
katham ekatāyām asiddhāyām dvayam eva na vidyate

84. yatra dvitīyaḥ na asti hi tatra ekasya ekatā
katham ekatāyām asiddhāyām dvayam eva na vidyate

84. Where indeed there is no second entity, how can the oneness of the one (unity) be asserted? If oneness is not established, then duality itself cannot exist.

Words meanings summery:

• यत्र (yatra) - where, in which

• न (na) - not, no

• अस्ति (asti) - is, exists

• द्वितीयः (dvitīyaḥ) - second, another, a rival

• हि (hi) - indeed, surely, for

• तत्र (tatra) - there, in that place

• एकस्य (ekasya) - of one, of the single one

• एकता (ekatā) - oneness, unity, identity

• कथम् (katham) - how? in what way?

• एकतायाम् (ekatāyām) - when oneness is... (in oneness, in unity)

• असिद्धायाम् (asiddhāyām) - not established, not proven, unaccomplished

• द्वयम् (dvayam) - a pair, duality, the state of being two

• एव (eva) - indeed, only, just

• न (na) - not, no

• विद्यते (vidyate) - exists, is found

Words meanings and morphology

यत्र (yatra) - where, in which

(indeclinable)

न (na) - not, no

(indeclinable)

अस्ति (asti) - is, exists

(verb)

3rd person , singular, active, present (lat) of as

Root: as (class 2)

द्वितीयः (dvitīyaḥ) - second, another, a rival

(adjective)

Nominative, masculine, singular of dvitīya

dvitīya - second, another, a rival

हि (hi) - indeed, surely, for

(indeclinable)

तत्र (tatra) - there, in that place

(indeclinable)

एकस्य (ekasya) - of one, of the single one

(numeral)

एकता (ekatā) - oneness, unity, identity

(noun)

Nominative, feminine, singular of ekatā

ekatā - oneness, unity, identity

Derived from 'eka' (one) with the suffix '-tā'

कथम् (katham) - how? in what way?

(indeclinable)

एकतायाम् (ekatāyām) - when oneness is... (in oneness, in unity)

(noun)

Locative, feminine, singular of ekatā

ekatā - oneness, unity, identity

Derived from 'eka' (one) with the suffix '-tā'

Note: Used in a locative absolute construction

असिद्धायाम् (asiddhāyām) - not established, not proven, unaccomplished

(adjective)

Locative, feminine, singular of asiddha

asiddha - not established, not proven, unaccomplished

Past Passive Participle

Negated (a-) past passive participle of root 'sidh' (to accomplish, prove)

Compound type : nañ-tatpuruṣa (a+siddha)

• a – not, non-, un-
  indeclinable
• siddha – accomplished, established, proven, perfected
  adjective (masculine)
  Past Passive Participle
  Past passive participle of root 'sidh' (to accomplish, prove)
  Root: sidh (class 1)

Note: Used in a locative absolute construction, agreeing with 'ekatāyām'

द्वयम् (dvayam) - a pair, duality, the state of being two

(noun)

Nominative, neuter, singular of dvaya

dvaya - a pair, duality, the state of being two

एव (eva) - indeed, only, just

(indeclinable)

न (na) - not, no

(indeclinable)

विद्यते (vidyate) - exists, is found

(verb)

3rd person , singular, middle, present (lat) of vid

Root: vid (class 4)