योगवासिष्ठः yogavāsiṣṭhaḥ - book-1, chapter-27, verse-18

पर्णानि जीर्णानि यथा तरूणां समेत्य जन्माशु लयं प्रयान्ति ।
तथैव लोकाः स्वविवेकहीनाः समेत्य गच्छन्ति कुतोऽप्यहोभिः ॥ १८ ॥

parṇāni jīrṇāni yathā tarūṇāṃ sametya janmāśu layaṃ prayānti ,
tathaiva lokāḥ svavivekahīnāḥ sametya gacchanti kuto'pyahobhiḥ 18

18. parṇāni jīrṇāni yathā tarūṇām
sametya janmā āśu layaṃ prayānti |
tathaiva lokāḥ svavivekahīnāḥ
sametya gacchanti kutaḥ api ahobhiḥ

18. yathā tarūṇām jīrṇāni parṇāni janmā sametya āśu layaṃ prayānti tathaiva svavivekahīnāḥ lokāḥ sametya ahobhiḥ kutaḥ api gacchanti.

18. Just as old, withered leaves of trees, after emerging, quickly move towards decay, similarly, people devoid of their own discernment (viveka), after coming into being, somehow vanish with the passing of days.

Words meanings summery:

• पर्णानि (parṇāni) - leaves

• जीर्णानि (jīrṇāni) - old, withered, decayed, worn out

• यथा (yathā) - as, just as, according to

• तरूणाम् (tarūṇām) - of trees

• समेत्य (sametya) - having come into existence (birth) (having come together, having obtained, having arrived)

• जन्मा (janmā) - appearance/existence (birth, existence, origin)

• आशु (āśu) - quickly, swiftly

• लयं (layaṁ) - dissolution, merging, decay, end

• प्रयान्ति (prayānti) - they go towards dissolution, they decay (they go, they move towards, they attain)

• तथैव (tathaiva) - in the same way, similarly

• लोकाः (lokāḥ) - people (people, worlds, folks)

• स्वविवेकहीनाः (svavivekahīnāḥ) - devoid of their own discernment, lacking self-discrimination

• समेत्य (sametya) - having come into existence (having come together, having obtained, having arrived)

• गच्छन्ति (gacchanti) - they pass away, they vanish (they go, they move, they proceed)

• कुतः (kutaḥ) - somehow, from somewhere (whence, from where, how, why)

• अपि (api) - somehow (in combination with kutaḥ) (also, even, perhaps, though)

• अहोभिः (ahobhiḥ) - with the passing of days (by days, through the days, with the days)

Words meanings and morphology

पर्णानि (parṇāni) - leaves

(noun)

neuter, plural of parṇa

parṇa - leaf, feather, wing, blade of grass

जीर्णानि (jīrṇāni) - old, withered, decayed, worn out

(adjective)

neuter, plural of jīrṇa

jīrṇa - old, withered, decayed, worn out, digested

Past Passive Participle

Derived from root jṝ (to decay, grow old) with suffix -ta

Root: jṝ (class 1)

Note: Agrees with 'parṇāni'.

यथा (yathā) - as, just as, according to

(indeclinable)

तरूणाम् (tarūṇām) - of trees

(noun)

Genitive, masculine, plural of taru

taru - tree, plant

समेत्य (sametya) - having come into existence (birth) (having come together, having obtained, having arrived)

(indeclinable)

Absolutive (Gerund)

Derived from root i (to go) with prefix sam and suffix -tya

Prefix: sam

Root: i (class 2)

जन्मा (janmā) - appearance/existence (birth, existence, origin)

(noun)

Accusative, neuter, singular of janman

janman - birth, origin, existence, life

Root: jan (class 4)

Note: Direct object of the action implied by 'sametya'.

आशु (āśu) - quickly, swiftly

(indeclinable)

लयं (layaṁ) - dissolution, merging, decay, end

(noun)

Accusative, masculine, singular of laya

laya - dissolution, merging, melting, end, disappearance, decay

Root: lī (class 4)

Note: Object of 'prayānti'.

प्रयान्ति (prayānti) - they go towards dissolution, they decay (they go, they move towards, they attain)

(verb)

3rd person , plural, active, present indicative (laṭ) of prayā

Prefix: pra

Root: yā (class 2)

Note: Subject is 'parṇāni'.

तथैव (tathaiva) - in the same way, similarly

(indeclinable)

Sandhi of tathā + eva

लोकाः (lokāḥ) - people (people, worlds, folks)

(noun)

Nominative, masculine, plural of loka

loka - world, people, folk, realm

Note: Subject of 'gacchanti'.

स्वविवेकहीनाः (svavivekahīnāḥ) - devoid of their own discernment, lacking self-discrimination

(adjective)

Nominative, masculine, plural of svavivekahīna

svavivekahīna - devoid of one's own discernment/discrimination

Compound type : tatpurusha (sva+viveka+hīna)

• sva – own, self
  pronoun
• viveka – discrimination, discernment, discretion (viveka)
  noun (masculine)
  Prefix: vi
  Root: vic (class 7)
• hīna – devoid of, deprived of, deficient, left, abandoned
  adjective
  Past Passive Participle
  Derived from root hā (to abandon, leave) with suffix -ta
  Root: hā (class 3)

Note: Agrees with 'lokāḥ'.

समेत्य (sametya) - having come into existence (having come together, having obtained, having arrived)

(indeclinable)

Absolutive (Gerund)

Derived from root i (to go) with prefix sam and suffix -tya

Prefix: sam

Root: i (class 2)

Note: Refers to 'lokāḥ'.

गच्छन्ति (gacchanti) - they pass away, they vanish (they go, they move, they proceed)

(verb)

3rd person , plural, active, present indicative (laṭ) of gam

Root: gam (class 1)

Note: Subject is 'lokāḥ'.

कुतः (kutaḥ) - somehow, from somewhere (whence, from where, how, why)

(indeclinable)

Ablative form of the interrogative pronoun 'kim' (what)

अपि (api) - somehow (in combination with kutaḥ) (also, even, perhaps, though)

(indeclinable)

अहोभिः (ahobhiḥ) - with the passing of days (by days, through the days, with the days)

(noun)

Instrumental, neuter, plural of ahan

ahan - day

Note: Denotes the means or accompanying circumstance.