महाभारतः mahābhārataḥ - book-12, chapter-322, verse-37

प्रवृत्तौ च निवृत्तौ च योनिरेतद्भविष्यति ।
ऋग्यजुःसामभिर्जुष्टमथर्वाङ्गिरसैस्तथा ॥३७॥

37. pravṛttau ca nivṛttau ca yoniretadbhaviṣyati ,
ṛgyajuḥsāmabhirjuṣṭamatharvāṅgirasaistathā.

37. pravṛttau ca nivṛttau ca yoniḥ etat bhaviṣyati
ṛgyajuḥsāmabhiḥ juṣṭam atharvāṅgirasaiḥ tathā

37. etat pravṛttau ca nivṛttau ca yoniḥ bhaviṣyati
ṛgyajuḥsāmabhiḥ tathā atharvāṅgirasaiḥ juṣṭam

37. This (work) will be the source for both engagement and disengagement (from worldly life), endowed as it is with the Ṛg, Yajur, and Sāma Vedas, and similarly with the Atharvāṅgiras.

Words meanings summery:

• प्रवृत्तौ (pravṛttau) - in engagement (with worldly life) (in activity, in engagement, in origin)

• च (ca) - and (and, also)

• निवृत्तौ (nivṛttau) - in disengagement (from worldly life) (in cessation, in disengagement, in renunciation)

• च (ca) - and (and, also)

• योनिः (yoniḥ) - the source (source, origin, womb, place of birth)

• एतत् (etat) - this (work) (this, this one)

• भविष्यति (bhaviṣyati) - will be (will be, will become)

• ऋग्यजुःसामभिः (ṛgyajuḥsāmabhiḥ) - by the Ṛg, Yajur, and Sāma Vedas

• जुष्टम् (juṣṭam) - endowed (with) (attended, endowed, liked, served)

• अथर्वाङ्गिरसैः (atharvāṅgirasaiḥ) - by the Atharvāṅgiras (Vedas) (by the Atharvan and Angiras, by the Atharvaveda)

• तथा (tathā) - similarly, also (thus, so, in that manner, also, similarly)

Words meanings and morphology

प्रवृत्तौ (pravṛttau) - in engagement (with worldly life) (in activity, in engagement, in origin)

(noun)

Locative, feminine, singular of pravṛtti

pravṛtti - activity, origin, evolution, engagement, worldly life

From pra- √vṛt (to turn, exist) + -ti suffix.

Prefix: pra

Root: vṛt (class 1)

च (ca) - and (and, also)

(indeclinable)

Conjunction, used twice to connect two elements.

निवृत्तौ (nivṛttau) - in disengagement (from worldly life) (in cessation, in disengagement, in renunciation)

(noun)

Locative, feminine, singular of nivṛtti

nivṛtti - cessation, abstention, renunciation, turning back, withdrawal

From ni- √vṛt (to turn, cease) + -ti suffix.

Prefix: ni

Root: vṛt (class 1)

च (ca) - and (and, also)

(indeclinable)

Conjunction.

योनिः (yoniḥ) - the source (source, origin, womb, place of birth)

(noun)

Nominative, masculine, singular of yoni

yoni - source, origin, womb, place of birth, family

एतत् (etat) - this (work) (this, this one)

(pronoun)

Nominative, neuter, singular of etad

etad - this

Demonstrative pronoun, nominative singular neuter.

भविष्यति (bhaviṣyati) - will be (will be, will become)

(verb)

3rd person , singular, active, future (lṛṭ) of bhū

Future tense (lṛṭ) 3rd singular

From root √bhū (to be).

Root: bhū (class 1)

ऋग्यजुःसामभिः (ṛgyajuḥsāmabhiḥ) - by the Ṛg, Yajur, and Sāma Vedas

(noun)

Instrumental, neuter, plural of ṛgyajuḥsāman

ṛgyajuḥsāman - the Ṛgveda, Yajurveda, and Sāmaveda (collectively)

Dvandva compound of ṛc (Ṛgveda), yajus (Yajurveda), and sāman (Sāmaveda).

Compound type : dvandva (ṛc+yajus+sāman)

• ṛc – verse, hymn (specifically of the Ṛgveda)
  noun (feminine)
• yajus – prose formula (specifically of the Yajurveda)
  noun (neuter)
• sāman – melody, chant (specifically of the Sāmaveda)
  noun (neuter)

जुष्टम् (juṣṭam) - endowed (with) (attended, endowed, liked, served)

(adjective)

Nominative, neuter, singular of juṣṭa

juṣṭa - liked, agreeable, attended, served, endowed, frequented

Past Passive Participle

From root √juṣ (to like, enjoy, attend, frequent).

Root: juṣ (class 1)

अथर्वाङ्गिरसैः (atharvāṅgirasaiḥ) - by the Atharvāṅgiras (Vedas) (by the Atharvan and Angiras, by the Atharvaveda)

(noun)

Instrumental, masculine, plural of atharvāṅgirasa

atharvāṅgirasa - relating to Atharvan and Angiras, the Atharvaveda

Compound referring to the Atharvaveda, traditionally associated with the seers Atharvan and Angiras.

Compound type : dvandva (atharvan+aṅgiras)

• atharvan – name of an ancient seer, priest, associated with Atharvaveda
  proper noun (masculine)
• aṅgiras – name of an ancient seer, family of priests
  proper noun (masculine)

तथा (tathā) - similarly, also (thus, so, in that manner, also, similarly)

(indeclinable)

Correlative adverb/particle.