योगवासिष्ठः yogavāsiṣṭhaḥ - book-6, chapter-30, verse-95

ऋतुचक्रं प्रवहति सहसा कालमण्डलम् ।
दिनरात्रितयोपैति तेजस्तिमिरतां क्रमात् ॥ ९५ ॥

ṛtucakraṃ pravahati sahasā kālamaṇḍalam ,
dinarātritayopaiti tejastimiratāṃ kramāt 95

95. ṛtucakram pravahati sahasā kālamaṇḍalam
dinarātritayā upaiti tejas timiratām kramāt

95. ṛtucakram kālamaṇḍalam sahasā pravahati
tejas dinarātritayā kramāt timiratām upaiti

95. The cycle of seasons and the sphere of time swiftly move on. Light gradually transforms into darkness through the succession of day and night.

Words meanings summery:

• ऋतुचक्रम् (ṛtucakram) - cycle of seasons

• प्रवहति (pravahati) - flows, moves on, proceeds

• सहसा (sahasā) - swiftly, suddenly, by force

• कालमण्डलम् (kālamaṇḍalam) - sphere of time, cycle of time

• दिनरात्रितया (dinarātritayā) - by day and night, through the state/succession of day and night

• उपैति (upaiti) - transforms into (approaches, obtains, comes to, goes to, attains)

• तेजस् (tejas) - light (light, brilliance, energy, splendor)

• तिमिरताम् (timiratām) - to darkness, state of darkness

• क्रमात् (kramāt) - gradually, in succession, in due order

Words meanings and morphology

ऋतुचक्रम् (ṛtucakram) - cycle of seasons

(noun)

Nominative, neuter, singular of ṛtucakra

ṛtucakra - cycle of seasons

Compound type : tatpuruṣa (ṛtu+cakra)

• ṛtu – season
  noun (masculine)
• cakra – wheel, cycle
  noun (neuter)

Note: Subject of pravahati implicitly along with kālamaṇḍalam.

प्रवहति (pravahati) - flows, moves on, proceeds

(verb)

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

Present Indicative, Parasmaipada

root vah, with prefix pra-, parasmaipada, present tense, 3rd person singular

Prefix: pra

Root: vah (class 1)

Note: Subject is ṛtucakram and kālamaṇḍalam.

सहसा (sahasā) - swiftly, suddenly, by force

(indeclinable)

instrumental of sahas (strength, force) used as adverb

कालमण्डलम् (kālamaṇḍalam) - sphere of time, cycle of time

(noun)

Nominative, neuter, singular of kālamaṇḍala

kālamaṇḍala - sphere of time, cycle of time, duration

Compound type : tatpuruṣa (kāla+maṇḍala)

• kāla – time, destiny
  noun (masculine)
• maṇḍala – circle, sphere, disc, cycle
  noun (neuter)

Note: Subject of pravahati, along with ṛtucakram.

दिनरात्रितया (dinarātritayā) - by day and night, through the state/succession of day and night

(noun)

Instrumental, feminine, singular of dinarātritā

dinarātritā - state of being day and night, succession of day and night

from dina (day) + rātri (night) + -tā (suffix for state/quality)

Compound type : tatpuruṣa (dina+rātri+-tā)

• dina – day
  noun (neuter)
• rātri – night
  noun (feminine)
• -tā – state, quality (suffix)
  suffix (feminine)

Note: Explains the means or manner.

उपैति (upaiti) - transforms into (approaches, obtains, comes to, goes to, attains)

(verb)

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

Present Indicative, Parasmaipada

root i, with prefix upa-, parasmaipada, present tense, 3rd person singular

Prefix: upa

Root: i (class 2)

Note: Subject is tejas.

तेजस् (tejas) - light (light, brilliance, energy, splendor)

(noun)

Nominative, neuter, singular of tejas

tejas - light, brilliance, energy, splendor, vital power

Note: The subject of 'upaiti'.

तिमिरताम् (timiratām) - to darkness, state of darkness

(noun)

Accusative, feminine, singular of timiratā

timiratā - darkness, state of darkness

from timira (dark) + -tā (suffix for state/quality)

Compound type : tatpuruṣa (timira+-tā)

• timira – dark, blind; darkness
  noun (neuter)
• -tā – state, quality (suffix)
  suffix (feminine)

Note: Object of 'upaiti'.

क्रमात् (kramāt) - gradually, in succession, in due order

(indeclinable)

Note: Adverbial usage of ablative.