महाभारतः mahābhārataḥ - book-12, chapter-299, verse-6

एतस्यापि च संख्यानं वेदवेदाङ्गपारगैः ।
दश कल्पसहस्राणि पादोनान्यहरुच्यते ।
रात्रिमेतावतीं चास्य प्राहुरध्यात्मचिन्तकाः ॥६॥

6. etasyāpi ca saṁkhyānaṁ vedavedāṅgapāragaiḥ ,
daśa kalpasahasrāṇi pādonānyaharucyate ,
rātrimetāvatīṁ cāsya prāhuradhyātmacintakāḥ.

6. etasya api ca saṃkhyānam
vedavedāṅgapāragaiḥ daśa kalpasahasrāṇi
pādonāni ahaḥ ucyate rātrim etāvatīm
ca asya prāhuḥ adhyātmacintakāḥ

6. ca etasya api saṃkhyānam
vedavedāṅgapāragaiḥ ahaḥ daśa kalpasahasrāṇi
pādonāni ucyate ca adhyātmacintakāḥ
asya etāvatīm rātrim prāhuḥ

6. Moreover, its duration (saṃkhyānam) is declared by those proficient in the Vedas and Vedangas (vedavedāṅgapāraga) to be ten thousand Kalpas, less a quarter, as a 'day'. Spiritual thinkers (adhyātmacintaka) also state its night to be of the same duration.

Words meanings summery:

• एतस्य (etasya) - of this cosmic day (of this)

• अपि (api) - moreover (also, even)

• च (ca) - moreover (and, also)

• संख्यानम् (saṁkhyānam) - the specific duration or calculation (reckoning, calculation, duration)

• वेदवेदाङ्गपारगैः (vedavedāṅgapāragaiḥ) - by the experts in Vedic lore (by those who have mastered the Vedas and Vedangas)

• दश (daśa) - ten

• कल्पसहस्राणि (kalpasahasrāṇi) - ten thousand Kalpas (thousands of Kalpas)

• पादोनानि (pādonāni) - deficient by one quarter (of a thousand Kalpas) (less a quarter, lacking a fourth)

• अहः (ahaḥ) - a cosmic day (of Brahma) (day)

• उच्यते (ucyate) - is said, is declared, is called

• रात्रिम् (rātrim) - a cosmic night (night)

• एतावतीम् (etāvatīm) - of this same duration (as the day) (of such a duration, this much)

• च (ca) - and, also

• अस्य (asya) - of this (day's cosmic cycle) (of this, its)

• प्राहुः (prāhuḥ) - they say, they declare

• अध्यात्मचिन्तकाः (adhyātmacintakāḥ) - philosophers or sages focused on the spirit (ātman) (spiritual thinkers, contemplators of the self)

Words meanings and morphology

एतस्य (etasya) - of this cosmic day (of this)

(pronoun)

Genitive, neuter, singular of etad

etad - this, that

अपि (api) - moreover (also, even)

(indeclinable)

च (ca) - moreover (and, also)

(indeclinable)

संख्यानम् (saṁkhyānam) - the specific duration or calculation (reckoning, calculation, duration)

(noun)

Nominative, neuter, singular of saṃkhyāna

saṁkhyāna - reckoning, calculation, enumeration, duration

Derived from sam- + √khyā (to be called, to tell).

Prefix: sam

Root: khyā (class 2)

वेदवेदाङ्गपारगैः (vedavedāṅgapāragaiḥ) - by the experts in Vedic lore (by those who have mastered the Vedas and Vedangas)

(noun)

Instrumental, masculine, plural of vedavedāṅgapāraga

vedavedāṅgapāraga - one who has gone to the other shore/mastered the Vedas and Vedangas

Compound type : tatpuruṣa (veda+vedāṅga+pāraga)

• veda – knowledge, sacred knowledge, a Veda
  noun (masculine)
  Derived from √vid (to know) + a (suffix).
  Root: vid (class 2)
• vedāṅga – limb of the Veda, auxiliary science of the Veda
  noun (neuter)
  Compound of Veda (sacred knowledge) and Anga (limb, part).
• pāraga – one who has reached the other shore, proficient, expert
  adjective (masculine)
  Derived from pāra (shore) + √gam (to go) + a (suffix).
  Root: gam (class 1)

दश (daśa) - ten

(numeral)

कल्पसहस्राणि (kalpasahasrāṇi) - ten thousand Kalpas (thousands of Kalpas)

(noun)

Accusative, neuter, plural of kalpasahasra

kalpasahasra - a thousand Kalpas

Compound type : tatpuruṣa (kalpa+sahasra)

• kalpa – a Kalpa, an eon, a cosmic age
  noun (masculine)
  Derived from √kḷp (to be in order, to happen).
  Root: kḷp (class 10)
• sahasra – thousand
  numeral (neuter)

पादोनानि (pādonāni) - deficient by one quarter (of a thousand Kalpas) (less a quarter, lacking a fourth)

(adjective)

Accusative, neuter, plural of pādona

pādona - less a quarter, deficient by a fourth part

Compound type : tatpuruṣa (pāda+ūna)

• pāda – foot, quarter, fourth part
  noun (masculine)
• ūna – less, deficient, wanting
  adjective (neuter)
  Past Passive Participle
  From the root √ūna (to diminish, be lacking).
  Root: ūna

Note: Qualifies 'kalpasahasrāṇi'.

अहः (ahaḥ) - a cosmic day (of Brahma) (day)

(noun)

Nominative, neuter, singular of ahan

ahan - day

उच्यते (ucyate) - is said, is declared, is called

(verb)

3rd person , singular, passive, present (laṭ) of vac

Present Passive, Ātmanepada, 3rd person singular

Passive stem ucya + te.

Root: vac (class 2)

रात्रिम् (rātrim) - a cosmic night (night)

(noun)

Accusative, feminine, singular of rātri

rātri - night

एतावतीम् (etāvatīm) - of this same duration (as the day) (of such a duration, this much)

(adjective)

Accusative, feminine, singular of etāvat

etāvat - so much, so great, of such a quantity/duration

Derived from etad + -āvat (suffix).

च (ca) - and, also

(indeclinable)

अस्य (asya) - of this (day's cosmic cycle) (of this, its)

(pronoun)

Genitive, neuter, singular of idam

idam - this, this one

प्राहुः (prāhuḥ) - they say, they declare

(verb)

3rd person , plural, active, perfect (lit) of prabrū

Perfect Active, Parasmaipada, 3rd person plural

From pra- + √brū (to speak); an irregular perfect form.

Prefix: pra

Root: brū (class 2)

अध्यात्मचिन्तकाः (adhyātmacintakāḥ) - philosophers or sages focused on the spirit (ātman) (spiritual thinkers, contemplators of the self)

(noun)

Nominative, masculine, plural of adhyātmacintaka

adhyātmacintaka - one who meditates on the self/spirit, a spiritual thinker

Compound type : tatpuruṣa (adhyātman+cintaka)

• adhyātman – the supreme spirit, the individual soul (ātman), pertaining to the self
  noun (masculine)
  Compound: adhi (over, concerning) + ātman (self, spirit).
  Prefix: adhi
• cintaka – thinker, meditator, one who reflects
  noun (masculine)
  Agent noun
  Derived from √cint (to think, reflect).
  Root: cint (class 10)