महाभारतः mahābhārataḥ - book-14, chapter-66, verse-16

त्वं हि केशव धर्मात्मा सत्यवान्सत्यविक्रमः ।
स तां वाचमृतां कर्तुमर्हसि त्वमरिंदम ॥१६॥

16. tvaṁ hi keśava dharmātmā satyavānsatyavikramaḥ ,
sa tāṁ vācamṛtāṁ kartumarhasi tvamariṁdama.

16. tvam hi keśava dharma-ātmā satyavān satya-vikramaḥ
saḥ tām vācam amṛtām kartum arhasi tvam arim-dama

16. keśava,
tvam hi dharma-ātmā satyavān satya-vikramaḥ.
arim-dama,
tvam saḥ tām vācam amṛtām kartum arhasi.

16. Indeed, O Keśava, you are one whose inner nature (dharma) is righteousness, who is truthful, and whose prowess is unwavering. Therefore, O vanquisher of foes, you ought to make that word of yours unfailing.

Words meanings summery:

• त्वम् (tvam) - Refers to Krishna (you)

• हि (hi) - indeed, for, because

• केशव (keśava) - Addressed to Krishna (O Keśava (epithet of Krishna))

• धर्म-आत्मा (dharma-ātmā) - Refers to Krishna's inherent righteous nature (one whose inner nature (dharma) is righteousness, righteous-souled)

• सत्यवान् (satyavān) - Refers to Krishna's truthful nature (truthful, possessing truth)

• सत्य-विक्रमः (satya-vikramaḥ) - Refers to Krishna's unfailing strength and courage (whose prowess is unwavering/true valor)

• सः (saḥ) - Functions as a conjunction meaning "therefore" or "hence" (he, that, therefore)

• ताम् (tām) - Refers to a specific promise or statement made by Krishna (that, her)

• वाचम् (vācam) - Refers to a promise or assurance given by Krishna regarding the Pandava lineage (word, speech)

• अमृताम् (amṛtām) - Refers to the word/promise, meaning it should be made true and lasting (immortal, unfailing, divine)

• कर्तुम् (kartum) - to do, to make

• अर्हसि (arhasi) - you ought, you are able, you deserve

• त्वम् (tvam) - Refers to Krishna, repetition for emphasis (you)

• अरिम्-दम (arim-dama) - Addressed to Krishna (O vanquisher of foes, O subduer of enemies)

Words meanings and morphology

त्वम् (tvam) - Refers to Krishna (you)

(pronoun)

Nominative, singular of tvam

tvam - you (singular)

हि (hi) - indeed, for, because

(indeclinable)

Note: Emphatic particle.

केशव (keśava) - Addressed to Krishna (O Keśava (epithet of Krishna))

(proper noun)

Vocative, masculine, singular of keśava

keśava - an epithet of Vishnu/Krishna (long-haired, or slayer of Keśī demon)

धर्म-आत्मा (dharma-ātmā) - Refers to Krishna's inherent righteous nature (one whose inner nature (dharma) is righteousness, righteous-souled)

(noun)

Nominative, masculine, singular of dharma-ātman

dharma-ātman - righteous-souled, one whose inner nature (dharma) is righteousness

Compound 'dharma' (righteousness, natural law) + 'ātman' (self, soul).

Compound type : bahuvrihi (dharma+ātman)

• dharma – righteousness, duty, natural law, intrinsic nature (dharma)
  noun (masculine)
  Root: dhṛ (class 1)
• ātman – self, soul, spirit, essence (ātman)
  noun (masculine)

सत्यवान् (satyavān) - Refers to Krishna's truthful nature (truthful, possessing truth)

(adjective)

Nominative, masculine, singular of satyavat

satyavat - truthful, possessing truth

From 'satya' (truth) with suffix 'matup'/'vatup'

सत्य-विक्रमः (satya-vikramaḥ) - Refers to Krishna's unfailing strength and courage (whose prowess is unwavering/true valor)

(adjective)

Nominative, masculine, singular of satya-vikrama

satya-vikrama - of true valor, whose prowess is unfailing

Compound 'satya' (truth, unfailing) + 'vikrama' (prowess, valor).

Compound type : bahuvrihi (satya+vikrama)

• satya – truth, true, real
  noun (neuter)
• vikrama – prowess, valor, strength, courage
  noun (masculine)
  Prefix: vi
  Root: kram (class 1)

सः (saḥ) - Functions as a conjunction meaning "therefore" or "hence" (he, that, therefore)

(pronoun)

Nominative, masculine, singular of tad

tad - that, he, she, it

ताम् (tām) - Refers to a specific promise or statement made by Krishna (that, her)

(pronoun)

Accusative, feminine, singular of tad

tad - that, he, she, it

वाचम् (vācam) - Refers to a promise or assurance given by Krishna regarding the Pandava lineage (word, speech)

(noun)

Accusative, feminine, singular of vāc

vāc - word, speech, voice, saying

अमृताम् (amṛtām) - Refers to the word/promise, meaning it should be made true and lasting (immortal, unfailing, divine)

(adjective)

Accusative, feminine, singular of amṛta

amṛta - immortal, nectar, unfailing

From 'a' (not) + 'mṛta' (dead).

Compound type : tatpurusha (a+mṛta)

• a – not, un-
  indeclinable
  Negative prefix
• mṛta – dead, deceased
  participle (masculine)
  Past Passive Participle
  From root 'mṛ' (to die) with suffix 'kta'
  Root: mṛ (class 6)

कर्तुम् (kartum) - to do, to make

(infinitive)

Note: Used with 'arhasi'.

अर्हसि (arhasi) - you ought, you are able, you deserve

(verb)

2nd person , singular, active, present (laṭ) of arh

Present Active Indicative

From root 'arh' (to be worthy)

Root: arh (class 1)

त्वम् (tvam) - Refers to Krishna, repetition for emphasis (you)

(pronoun)

Nominative, singular of tvam

tvam - you (singular)

अरिम्-दम (arim-dama) - Addressed to Krishna (O vanquisher of foes, O subduer of enemies)

(noun)

Vocative, masculine, singular of arim-dama

arim-dama - vanquisher of foes, subduer of enemies

Compound 'ari' (enemy) + 'dama' (subduer)

Compound type : upapada tatpurusha (ari+dama)

• ari – enemy, foe
  noun (masculine)
• dama – subduing, taming, subduer
  noun (masculine)
  Nominal derivative from root 'dam'
  From root 'dam' (to tame, subdue)
  Root: dam (class 4)