योगवासिष्ठः yogavāsiṣṭhaḥ - book-7, chapter-49, verse-4

द्वीन्दुवत्तापजलवत्केशोण्ड्रकवदम्बरे ।
विस्फुरन्त्यां जगद्भ्रान्तौ वासनाप्रत्ययः कुतः ॥ ४ ॥

dvīnduvattāpajalavatkeśoṇḍrakavadambare ,
visphurantyāṃ jagadbhrāntau vāsanāpratyayaḥ kutaḥ 4

4. dvi-indu-vat tāpajala-vat keśoṇḍraka-vat ambare
visphurantyām jagat-bhrāntau vāsanā-pratyayaḥ kutaḥ

4. ambare dvi-indu-vat tāpajala-vat keśoṇḍraka-vat (sati) jagat-bhrāntau visphurantyām,
vāsanā-pratyayaḥ kutaḥ (syāt)

4. Just as there are illusions in the sky like two moons, a mirage, or a perceived hair-net, when the delusion of the world (jagad-bhrānti) is vividly manifesting, from where can the conviction in latent tendencies (vāsanā-pratyaya) possibly arise?

Words meanings summery:

• द्वि-इन्दु-वत् (dvi-indu-vat) - referring to the optical illusion of seeing two moons instead of one (like two moons)

• तापजल-वत् (tāpajala-vat) - like water appearing due to heat, an optical illusion (like a mirage)

• केशोण्ड्रक-वत् (keśoṇḍraka-vat) - like the optical illusion of seeing floating hairs or a net when eyes are fatigued or diseased (like a hair-net illusion)

• अम्बरे (ambare) - in the sky, in the atmosphere

• विस्फुरन्त्याम् (visphurantyām) - while the world-delusion is appearing vividly (in the manifesting, in the appearing vividly)

• जगत्-भ्रान्तौ (jagat-bhrāntau) - in the world-delusion, in the illusion of the world

• वासना-प्रत्ययः (vāsanā-pratyayaḥ) - the notion or conviction arising from latent tendencies (vāsanā) (mental impression of desires, conviction in tendencies)

• कुतः (kutaḥ) - questioning the source or possibility of its existence (from where? how? why?)

Words meanings and morphology

द्वि-इन्दु-वत् (dvi-indu-vat) - referring to the optical illusion of seeing two moons instead of one (like two moons)

(indeclinable)

formed by adding the suffix -vat (like, as) to the compound dvi-indu (two moons)

Compound type : avyayībhāva (dvi+indu+vat)

• dvi – two
  numeral
• indu – moon, drop, camphor
  noun (masculine)
• vat – like, as, similar to
  indeclinable
  suffix forming adverbs or adjectives indicating similarity

तापजल-वत् (tāpajala-vat) - like water appearing due to heat, an optical illusion (like a mirage)

(indeclinable)

formed by adding the suffix -vat to the compound tāpajala

Compound type : avyayībhāva (tāpa+jala+vat)

• tāpa – heat, fever, pain, suffering
  noun (masculine)
  from root tap (to heat, suffer)
  Root: tap
• jala – water
  noun (neuter)
• vat – like, as, similar to
  indeclinable
  suffix forming adverbs or adjectives indicating similarity

केशोण्ड्रक-वत् (keśoṇḍraka-vat) - like the optical illusion of seeing floating hairs or a net when eyes are fatigued or diseased (like a hair-net illusion)

(indeclinable)

formed by adding the suffix -vat to the compound keśoṇḍraka (keśa + uṇḍraka)

Compound type : avyayībhāva (keśa+uṇḍraka+vat)

• keśa – hair
  noun (masculine)
• uṇḍraka – a net, a circle, a disease causing visual distortion
  noun (neuter)
• vat – like, as, similar to
  indeclinable
  suffix forming adverbs or adjectives indicating similarity

अम्बरे (ambare) - in the sky, in the atmosphere

(noun)

Locative, neuter, singular of ambara

ambara - sky, atmosphere, clothing

विस्फुरन्त्याम् (visphurantyām) - while the world-delusion is appearing vividly (in the manifesting, in the appearing vividly)

(adjective)

Locative, feminine, singular of visphurant

visphurant - manifesting, appearing, throbbing, flashing, sparkling

Present Active Participle

Derived from the root sphur (to throb, flash) with upasarga vi- (forth, apart)

Prefix: vi

Root: sphur (class 6)

जगत्-भ्रान्तौ (jagat-bhrāntau) - in the world-delusion, in the illusion of the world

(noun)

Locative, feminine, singular of jagat-bhrānti

jagat-bhrānti - world-delusion, illusion of the world

Compound type : tatpuruṣa (jagat+bhrānti)

• jagat – world, moving, living being
  noun (neuter)
  Present active participle from root gam (to go), used as a noun.
  Root: gam (class 1)
• bhrānti – illusion, delusion, error, confusion, wandering
  noun (feminine)
  From root bhram (to wander, to be confused)
  Root: bhram (class 1)

वासना-प्रत्ययः (vāsanā-pratyayaḥ) - the notion or conviction arising from latent tendencies (vāsanā) (mental impression of desires, conviction in tendencies)

(noun)

Nominative, masculine, singular of vāsanā-pratyaya

vāsanā-pratyaya - mental impression or conviction of desires/tendencies (vāsanā); recollection of latent tendencies

Compound type : tatpuruṣa (vāsanā+pratyaya)

• vāsanā – latent impression, subconscious tendency, desire, imagination, perfume
  noun (feminine)
  From root vas (to dwell, to perfume) or vāś (to sound). Here, referring to latent mental imprints.
  Root: vas (class 1)
• pratyaya – conviction, belief, mental impression, notion, suffix, trust
  noun (masculine)
  From root i (to go) with upasarga prati- (towards, against)
  Prefix: prati
  Root: i (class 2)

कुतः (kutaḥ) - questioning the source or possibility of its existence (from where? how? why?)

(indeclinable)

Ablative adverbial form of `kim` (what)