महाभारतः mahābhārataḥ - book-3, chapter-239, verse-20

बृहस्पत्युशनोक्तैश्च मन्त्रैर्मन्त्रविशारदाः ।
अथर्ववेदप्रोक्तैश्च याश्चोपनिषदि क्रियाः ।
मन्त्रजप्यसमायुक्तास्तास्तदा समवर्तयन् ॥२०॥

20. bṛhaspatyuśanoktaiśca mantrairmantraviśāradāḥ ,
atharvavedaproktaiśca yāścopaniṣadi kriyāḥ ,
mantrajapyasamāyuktāstāstadā samavartayan.

20. bṛhaspati-uśana-uktaiḥ ca mantraiḥ
mantra-viśāradāḥ atharvaveda-proktaiḥ
ca yāḥ ca upaniṣadi kriyāḥ
mantra-jāpya-samāyuktāḥ tāḥ tadā samavartayan

20. Then, the experts in sacred formulas (mantra) performed all those rites (kriyā) and practices which are taught by Bṛhaspati and Uśanas, proclaimed in the Atharvaveda, and found in the Upaniṣads, all of them combined with the chanting (jāpya) of sacred formulas (mantra).

Words meanings summery:

• बृहस्पति-उशन-उक्तैः (bṛhaspati-uśana-uktaiḥ) - by those spoken by Bṛhaspati and Uśanas

• च (ca) - and

• मन्त्रैः (mantraiḥ) - by means of sacred formulas (mantra)

• मन्त्र-विशारदाः (mantra-viśāradāḥ) - experts in sacred formulas (mantra)

• अथर्ववेद-प्रोक्तैः (atharvaveda-proktaiḥ) - by those proclaimed in the Atharvaveda

• च (ca) - and

• याः (yāḥ) - referring to kriyāḥ (which (feminine plural))

• च (ca) - and

• उपनिषदि (upaniṣadi) - in the Upaniṣads

• क्रियाः (kriyāḥ) - rites, actions, practices

• मन्त्र-जाप्य-समायुक्ताः (mantra-jāpya-samāyuktāḥ) - endowed with the chanting (jāpya) of sacred formulas (mantra)

• ताः (tāḥ) - referring to the kriyāḥ (rites) (those (feminine plural))

• तदा (tadā) - then, at that time

• समवर्तयन् (samavartayan) - they performed, they brought about, they executed

Words meanings and morphology

बृहस्पति-उशन-उक्तैः (bṛhaspati-uśana-uktaiḥ) - by those spoken by Bṛhaspati and Uśanas

(adjective)

Instrumental, masculine, plural of bṛhaspatyuśanokta

bṛhaspatyuśanokta - spoken by Bṛhaspati and Uśanas

Past Passive Participle

Compound adjective formed from Bṛhaspati, Uśanas, and ukta (P.P.P. of vac). Refers to the mantras/kriyās.

Compound type : tatpuruṣa (bṛhaspati+uśanas+ukta)

• bṛhaspati – Brihaspati (preceptor of the Devas)
  proper noun (masculine)
• uśanas – Uśanas, Shukra (preceptor of the Daityas)
  proper noun (masculine)
• ukta – spoken, said, told
  adjective (neuter)
  Past Passive Participle
  From root 'vac' (to speak)
  Root: vac (class 2)

च (ca) - and

(indeclinable)

मन्त्रैः (mantraiḥ) - by means of sacred formulas (mantra)

(noun)

Instrumental, masculine, plural of mantra

mantra - sacred formula, hymn, incantation, prayer

Root: man (class 4)

मन्त्र-विशारदाः (mantra-viśāradāḥ) - experts in sacred formulas (mantra)

(noun)

Nominative, masculine, plural of mantraviśārada

mantraviśārada - expert in sacred formulas, skilled in mantras

Compound noun describing a person skilled in mantras.

Compound type : tatpuruṣa (mantra+viśārada)

• mantra – sacred formula, hymn, incantation, prayer
  noun (masculine)
  Root: man (class 4)
• viśārada – skilled, expert, proficient
  adjective (masculine)

अथर्ववेद-प्रोक्तैः (atharvaveda-proktaiḥ) - by those proclaimed in the Atharvaveda

(adjective)

Instrumental, masculine, plural of atharvavedaprokta

atharvavedaprokta - proclaimed in the Atharvaveda

Past Passive Participle

Compound adjective formed from Atharvaveda and prokta (P.P.P. of pravac). Refers to the mantras/kriyās.

Compound type : tatpuruṣa (atharvaveda+prokta)

• atharvaveda – The Atharvaveda (one of the four Vedas)
  proper noun (masculine)
• prokta – proclaimed, declared, taught
  adjective (neuter)
  Past Passive Participle
  From root 'vac' with prefix 'pra'
  Prefix: pra
  Root: vac (class 2)

च (ca) - and

(indeclinable)

याः (yāḥ) - referring to kriyāḥ (which (feminine plural))

(pronoun)

Nominative, feminine, plural of yat

yat - which, who, what

Relative pronoun

च (ca) - and

(indeclinable)

उपनिषदि (upaniṣadi) - in the Upaniṣads

(noun)

Locative, feminine, singular of upaniṣad

upaniṣad - Upaniṣad (a class of philosophical treatises in the Vedas)

Prefixes: upa+ni

Root: sad (class 1)

क्रियाः (kriyāḥ) - rites, actions, practices

(noun)

Nominative, feminine, plural of kriyā

kriyā - action, ritual, rite, performance

From root 'kṛ' (to do)

Root: kṛ (class 8)

मन्त्र-जाप्य-समायुक्ताः (mantra-jāpya-samāyuktāḥ) - endowed with the chanting (jāpya) of sacred formulas (mantra)

(adjective)

Nominative, feminine, plural of mantrajāpyasamāyuktā

mantrajāpyasamāyuktā - joined with the chanting of sacred formulas

Bahuvrihi compound: 'Mantra-jāpya' (chanting of mantras) + 'samāyuktā' (joined with)

Compound type : bahuvrīhi (mantra+jāpya+samāyuktā)

• mantra – sacred formula, hymn, incantation, prayer
  noun (masculine)
  Root: man (class 4)
• jāpya – to be muttered/chanted/recited
  adjective (neuter)
  Gerundive
  From root 'jap' (to mutter, chant)
  Root: jap (class 1)
• samāyuktā – joined with, endowed with, possessed of
  adjective (feminine)
  Past Passive Participle
  From root 'yuj' with prefixes 'sam' and 'ā'
  Prefixes: sam+ā
  Root: yuj (class 7)

ताः (tāḥ) - referring to the kriyāḥ (rites) (those (feminine plural))

(pronoun)

Accusative, feminine, plural of tad

tad - that, those

Demonstrative pronoun

तदा (tadā) - then, at that time

(indeclinable)

Adverb formed from 'tad'

समवर्तयन् (samavartayan) - they performed, they brought about, they executed

(verb)

3rd person , plural, active, past imperfect (laṅ) of sam-vṛt

Imperfect, 3rd person plural, active voice. Root vṛt with prefix sam.

Prefix: sam

Root: vṛt (class 1)