योगवासिष्ठः yogavāsiṣṭhaḥ - book-6, chapter-19, verse-16

तानि कालं समासाद्य ततोऽण्डान्येकविंशतिः ।
गर्भाक्रान्त्या द्विधा जग्मुर्ब्रह्माण्डानीव सारवत् ॥ १६ ॥

tāni kālaṃ samāsādya tato'ṇḍānyekaviṃśatiḥ ,
garbhākrāntyā dvidhā jagmurbrahmāṇḍānīva sāravat 16

16. tāni kālam samāsādya tataḥ aṇḍāni ekaviṃśatiḥ
garbhākrāntyā dvidhā jagmuḥ brahmāṇḍāni iva sāravat

16. tāni ekaviṃśatiḥ aṇḍāni kālam samāsādya tataḥ
garbhākrāntyā dvidhā jagmuḥ sāravat brahmāṇḍāni iva

16. Those twenty-one eggs, having reached the appointed time, then split into two parts through the process of impregnation (or fetal development), much like substantial cosmic eggs (brahmāṇḍa).

Words meanings summery:

• तानि (tāni) - those, them

• कालम् (kālam) - time, season, period

• समासाद्य (samāsādya) - having reached, having attained, having approached

• ततः (tataḥ) - then, thence, from that

• अण्डानि (aṇḍāni) - eggs

• एकविंशतिः (ekaviṁśatiḥ) - twenty-one

• गर्भाक्रान्त्या (garbhākrāntyā) - by impregnation, by fetal development

• द्विधा (dvidhā) - in two parts, in two ways

• जग्मुः (jagmuḥ) - they split (they went, they moved, they attained)

• ब्रह्माण्डानि (brahmāṇḍāni) - cosmic eggs, universal eggs

• इव (iva) - like, as, as if

• सारवत् (sāravat) - substantial, essential, significant

Words meanings and morphology

तानि (tāni) - those, them

(pronoun)

Nominative, neuter, plural of tat

tat - that, those

Note: Refers to the twenty-one eggs.

कालम् (kālam) - time, season, period

(noun)

Accusative, masculine, singular of kāla

kāla - time, duration, period, death

समासाद्य (samāsādya) - having reached, having attained, having approached

(indeclinable)

Absolutive/Gerund

Formed from sam-ā-√sad + -ya suffix for absolutive in compound verbs.

Prefixes: sam+ā

Root: sad (class 1)

Note: Absolutive indicates prior action.

ततः (tataḥ) - then, thence, from that

(indeclinable)

अण्डानि (aṇḍāni) - eggs

(noun)

Nominative, neuter, plural of aṇḍa

aṇḍa - egg, testicle

एकविंशतिः (ekaviṁśatiḥ) - twenty-one

(numeral)

Compound type : karmadhāraya (eka+viṃśati)

• eka – one, single
  numeral/adjective
• viṃśati – twenty
  numeral/noun (feminine)

Note: Grammatically treated as a singular collective.

गर्भाक्रान्त्या (garbhākrāntyā) - by impregnation, by fetal development

(noun)

Instrumental, feminine, singular of garbhākrānti

garbhākrānti - impregnation, fetal development, attack by embryo

Compound type : tatpuruṣa (garbha+ākrānti)

• garbha – womb, embryo, fetus, interior
  noun (masculine)
• ākrānti – attack, invasion, overpowering, entering
  noun (feminine)
  action noun
  From ā-√kram + -ti
  Prefix: ā
  Root: kram (class 1)

द्विधा (dvidhā) - in two parts, in two ways

(indeclinable)

जग्मुः (jagmuḥ) - they split (they went, they moved, they attained)

(verb)

3rd person , plural, active, perfect (Lit) of gam

Root: gam (class 1)

ब्रह्माण्डानि (brahmāṇḍāni) - cosmic eggs, universal eggs

(noun)

Nominative, neuter, plural of brahmāṇḍa

brahmāṇḍa - cosmic egg, universal egg (brahmāṇḍa)

Compound type : tatpuruṣa (brahman+aṇḍa)

• brahman – Brahman, creator god Brahmā, sacred utterance
  noun (neuter/masculine)
• aṇḍa – egg, testicle
  noun (neuter)

इव (iva) - like, as, as if

(indeclinable)

सारवत् (sāravat) - substantial, essential, significant

(adjective)

Nominative, neuter, plural of sāravat

sāravat - having essence, substantial, valuable

Possessive suffix -vat

Note: Agrees with 'brahmāṇḍāni'.