महाभारतः mahābhārataḥ - book-18, chapter-5, verse-31

पुण्योऽयमितिहासाख्यः पवित्रं चेदमुत्तमम् ।
कृष्णेन मुनिना विप्र नियतं सत्यवादिना ॥३१॥

31. puṇyo'yamitihāsākhyaḥ pavitraṁ cedamuttamam ,
kṛṣṇena muninā vipra niyataṁ satyavādinā.

31. puṇyaḥ ayam itihāsākhyaḥ pavitram ca idam
uttamam kṛṣṇena muninā vipra niyatam satyavādinā

31. O brahmin, this epic (itihāsa) is meritorious and supremely pure. It was composed by the (muni) Kṛṣṇa (Vyāsa), who is ever truthful.

Words meanings summery:

• पुण्यः (puṇyaḥ) - meritorious (referring to the epic) (meritorious, sacred, virtuous)

• अयम् (ayam) - this (epic) (this, he)

• इतिहासाख्यः (itihāsākhyaḥ) - called an epic (itihāsa) (called an epic, known as history)

• पवित्रम् (pavitram) - pure (referring to the epic) (pure, sacred)

• च (ca) - and

• इदम् (idam) - this (epic) (this)

• उत्तमम् (uttamam) - supremely excellent (supreme, excellent, best)

• कृष्णेन (kṛṣṇena) - by (the sage) Kṛṣṇa (Vyāsa) (by Kṛṣṇa, by Vyāsa)

• मुनिना (muninā) - by the (muni) (by a sage)

• विप्र (vipra) - O brahmin (addressing the listener, likely Ugraśravas Sauti) (O brahmin)

• नियतम् (niyatam) - ever, constantly (constantly, always, regulated)

• सत्यवादिना (satyavādinā) - by the one who is truthful (by the truthful one)

Words meanings and morphology

पुण्यः (puṇyaḥ) - meritorious (referring to the epic) (meritorious, sacred, virtuous)

(adjective)

Nominative, masculine, singular of puṇya

puṇya - meritorious, sacred, virtuous, pure

अयम् (ayam) - this (epic) (this, he)

(pronoun)

Nominative, masculine, singular of idam

idam - this, he

इतिहासाख्यः (itihāsākhyaḥ) - called an epic (itihāsa) (called an epic, known as history)

(adjective)

Nominative, masculine, singular of itihāsākhya

itihāsākhya - called 'history', named 'epic'

Compound type : tatpuruṣa (itihāsa+ākhya)

• itihāsa – history, epic narrative
  noun (masculine)
• ākhya – name, appellation, to be called
  noun (neuter)
  Gerundive
  From root khyā with prefix ā and suffix ya.
  Prefix: ā
  Root: khyā (class 2)

पवित्रम् (pavitram) - pure (referring to the epic) (pure, sacred)

(adjective)

Nominative, neuter, singular of pavitra

pavitra - pure, sacred, holy, cleansing

च (ca) - and

(indeclinable)

इदम् (idam) - this (epic) (this)

(pronoun)

Nominative, neuter, singular of idam

idam - this, he

उत्तमम् (uttamam) - supremely excellent (supreme, excellent, best)

(adjective)

Nominative, neuter, singular of uttama

uttama - supreme, excellent, best, highest

कृष्णेन (kṛṣṇena) - by (the sage) Kṛṣṇa (Vyāsa) (by Kṛṣṇa, by Vyāsa)

(proper noun)

Instrumental, masculine, singular of kṛṣṇa

kṛṣṇa - Kṛṣṇa (name of various persons, including Vyāsa, who was dark-skinned), black, dark

मुनिना (muninā) - by the (muni) (by a sage)

(noun)

Instrumental, masculine, singular of muni

muni - sage, ascetic, silent one

Root: man (class 4)

विप्र (vipra) - O brahmin (addressing the listener, likely Ugraśravas Sauti) (O brahmin)

(noun)

Vocative, masculine, singular of vipra

vipra - brahmin, priest, wise person

नियतम् (niyatam) - ever, constantly (constantly, always, regulated)

(indeclinable)

Past Passive Participle

From root yam with prefix ni and suffix kta. Used adverbially here.

Prefix: ni

Root: yam (class 1)

सत्यवादिना (satyavādinā) - by the one who is truthful (by the truthful one)

(adjective)

Instrumental, masculine, singular of satyavādin

satyavādin - truthful, speaking the truth

Agent Noun

From satya and root vad.

Compound type : tatpuruṣa (satya+vādin)

• satya – truth, true
  noun (neuter)
• vādin – speaker, announcer, disputant
  noun (masculine)
  Agent Noun
  Formed from root vad with suffix ṇini.
  Root: vad (class 1)

Note: Agrees with kṛṣṇena muninā.