महाभारतः mahābhārataḥ - book-3, chapter-78, verse-17

ततोऽक्षहृदयं प्रादात्पाण्डवाय महात्मने ।
दत्त्वा चाश्वशिरोऽगच्छदुपस्प्रष्टुं महातपाः ॥१७॥

17. tato'kṣahṛdayaṁ prādātpāṇḍavāya mahātmane ,
dattvā cāśvaśiro'gacchadupaspraṣṭuṁ mahātapāḥ.

17. tataḥ akṣahṛdayam prādāt pāṇḍavāya mahātmane
dattvā ca aśvaśiraḥ agacchat upasprastum mahātapaḥ

17. Then, the great ascetic (mahātapaḥ) imparted the secret knowledge of dice to the great-souled (mahātman) son of Pāṇḍu. After bestowing the knowledge of Aśvaśiras (the Horse's Head), he proceeded to perform his ritual ablutions.

Words meanings summery:

• ततः (tataḥ) - then, subsequently (then, therefrom, after that)

• अक्षहृदयम् (akṣahṛdayam) - the secret knowledge of dice (secret of dice, knowledge of gaming)

• प्रादात् (prādāt) - he imparted (he gave, he imparted)

• पाण्डवाय (pāṇḍavāya) - to the son of Pāṇḍu (to the son of Pāṇḍu, to Arjuna)

• महात्मने (mahātmane) - to the great-souled (mahātman) one (to the great-souled one, to the noble one)

• दत्त्वा (dattvā) - having given (having given, after giving)

• च (ca) - and, also

• अश्वशिरः (aśvaśiraḥ) - the knowledge of Aśvaśiras (the Horse's Head) (the Horse's Head (name of a specific knowledge/text/weapon))

• अगच्छत् (agacchat) - he proceeded (he went, he proceeded)

• उपस्प्रस्तुम् (upasprastum) - to perform ritual ablutions (to touch, to bathe, to perform ablutions)

• महातपः (mahātapaḥ) - the great ascetic (mahātapaḥ) (great ascetic, one with great penance)

Words meanings and morphology

ततः (tataḥ) - then, subsequently (then, therefrom, after that)

(indeclinable)

From pronominal base 'tad' + suffix '-tas'

अक्षहृदयम् (akṣahṛdayam) - the secret knowledge of dice (secret of dice, knowledge of gaming)

(noun)

Accusative, neuter, singular of akṣahṛdaya

akṣahṛdaya - secret of dice; knowledge of gaming

Compound type : tatpurusha (akṣa+hṛdaya)

• akṣa – dice; axle; sense organ
  noun (masculine)
• hṛdaya – heart; core; secret; knowledge
  noun (neuter)

Note: Can also be nominative singular neuter, but accusative fits context better as direct object.

प्रादात् (prādāt) - he imparted (he gave, he imparted)

(verb)

3rd person , singular, active, aorist (luṅ) of dā

Root 'dā' (class 3, 2), prefixed with 'pra'

Prefix: pra

Root: dā (class 3)

पाण्डवाय (pāṇḍavāya) - to the son of Pāṇḍu (to the son of Pāṇḍu, to Arjuna)

(noun)

Dative, masculine, singular of pāṇḍava

pāṇḍava - descendant of Pāṇḍu, son of Pāṇḍu

Derived from Pāṇḍu

Note: Refers to Arjuna in this context.

महात्मने (mahātmane) - to the great-souled (mahātman) one (to the great-souled one, to the noble one)

(adjective)

Dative, masculine, singular of mahātman

mahātman - great-souled, noble, illustrious

Compound type : bahuvrihi (mahā+ātman)

• mahā – great, large
  adjective
• ātman – self, soul, spirit, essence
  noun (masculine)

Note: Adjective qualifying Pāṇḍavāya.

दत्त्वा (dattvā) - having given (having given, after giving)

(indeclinable)

absolutive

Absolutive (gerund) of root 'dā'

Root: dā (class 3)

च (ca) - and, also

(indeclinable)

अश्वशिरः (aśvaśiraḥ) - the knowledge of Aśvaśiras (the Horse's Head) (the Horse's Head (name of a specific knowledge/text/weapon))

(noun)

Accusative, neuter, singular of aśvaśiras

aśvaśiras - Horse's Head; name of a divine weapon or knowledge

Compound type : tatpurusha (aśva+śiras)

• aśva – horse
  noun (masculine)
• śiras – head
  noun (neuter)

Note: Direct object of 'dattvā'.

अगच्छत् (agacchat) - he proceeded (he went, he proceeded)

(verb)

3rd person , singular, active, past imperfect (laṅ) of gam

Root 'gam' (class 1)

Root: gam (class 1)

उपस्प्रस्तुम् (upasprastum) - to perform ritual ablutions (to touch, to bathe, to perform ablutions)

(indeclinable)

infinitive

Infinitive of root 'spṛś' (class 6), prefixed with 'upa'

Prefix: upa

Root: spṛś (class 6)

Note: Infinitive expressing purpose.

महातपः (mahātapaḥ) - the great ascetic (mahātapaḥ) (great ascetic, one with great penance)

(adjective)

Nominative, masculine, singular of mahātapas

mahātapas - great ascetic; one who performs great penance

Compound type : bahuvrihi (mahā+tapas)

• mahā – great, large
  adjective
• tapas – penance, austerity, heat
  noun (neuter)

Note: Subject of the sentence, referring to Bṛhadaśva.