महाभारतः mahābhārataḥ - book-1, chapter-158, verse-19

तथा पितॄन्वैतरणी दुस्तरा पापकर्मभिः ।
गङ्गा भवति गन्धर्व यथा द्वैपायनोऽब्रवीत् ॥१९॥

19. tathā pitṝnvaitaraṇī dustarā pāpakarmabhiḥ ,
gaṅgā bhavati gandharva yathā dvaipāyano'bravīt.

19. tathā pitṝn vaitaraṇī dustarā pāpa-karmabhiḥ
gaṅgā bhavati gandharva yathā dvaipāyanaḥ abravīt

19. Similarly, O Gandharva, the Gaṅgā becomes the Vaitaraṇī river for the ancestors (pitṛ), difficult for sinners (pāpa-karman) to cross, just as Dvaipāyana (Vyāsa) has declared.

Words meanings summery:

• तथा (tathā) - thus, so, similarly

• पितॄन् (pitṝn) - Refers to the deceased ancestors whose realm the Vaitaraṇī river is associated with. (the ancestors)

• वैतरणी (vaitaraṇī) - The mythical river of the underworld that separates the living from the dead, difficult for sinners to cross. ((the river) Vaitaraṇī)

• दुस्तरा (dustarā) - Describing the Vaitaraṇī as hard to cross for sinners. (difficult to cross)

• पाप-कर्मभिः (pāpa-karmabhiḥ) - by those with sinful deeds, by sinners

• गङ्गा (gaṅgā) - the Gaṅgā river

• भवति (bhavati) - she becomes, she is

• गन्धर्व (gandharva) - O Gandharva

• यथा (yathā) - as, just as, according to

• द्वैपायनः (dvaipāyanaḥ) - The sage Vyāsa, author of the Mahābhārata. (Dvaipāyana (Vyāsa))

• अब्रवीत् (abravīt) - he said, he spoke

Words meanings and morphology

तथा (tathā) - thus, so, similarly

(indeclinable)

पितॄन् (pitṝn) - Refers to the deceased ancestors whose realm the Vaitaraṇī river is associated with. (the ancestors)

(noun)

Accusative, masculine, plural of pitṛ

pitṛ - father, ancestor (pitṛ)

वैतरणी (vaitaraṇī) - The mythical river of the underworld that separates the living from the dead, difficult for sinners to cross. ((the river) Vaitaraṇī)

(proper noun)

Nominative, feminine, singular of vaitaraṇī

vaitaraṇī - name of a mythical river in the underworld; difficult to cross

दुस्तरा (dustarā) - Describing the Vaitaraṇī as hard to cross for sinners. (difficult to cross)

(adjective)

Nominative, feminine, singular of dustara

dustara - difficult to cross, impassable

From dur- (difficult) + tara (crossing, from root tṛ)

Compound type : praādi-tatpuruṣa (dur+tara)

• dur – difficult, bad, hard
  indeclinable
• tara – crossing, leading across
  adjective (masculine)
  Agent noun/suffix
  from root tṛ (to cross)
  Root: tṛ (class 1)

Note: Agrees with 'Vaitaraṇī'

पाप-कर्मभिः (pāpa-karmabhiḥ) - by those with sinful deeds, by sinners

(noun)

Instrumental, masculine, plural of pāpa-karman

pāpa-karman - sinful action; one who performs sinful actions, sinner

Compound type : bahuvrīhi (pāpa+karman)

• pāpa – evil, wicked, sin, demerit
  noun (neuter)
• karman – action, deed, work (karma)
  noun (neuter)
  Root kṛ (to do) + suffix -man
  Root: kṛ (class 8)

Note: Literally 'by those whose actions are sinful'.

गङ्गा (gaṅgā) - the Gaṅgā river

(proper noun)

Nominative, feminine, singular of gaṅgā

gaṅgā - the Gaṅgā river (Ganges)

भवति (bhavati) - she becomes, she is

(verb)

3rd person , singular, active, present (laṭ) of bhū

Present Active

Root bhū (class 1)

Root: bhū (class 1)

गन्धर्व (gandharva) - O Gandharva

(proper noun)

Vocative, masculine, singular of gandharva

gandharva - Gandharva (a class of celestial beings, often musicians or singers)

यथा (yathā) - as, just as, according to

(indeclinable)

द्वैपायनः (dvaipāyanaḥ) - The sage Vyāsa, author of the Mahābhārata. (Dvaipāyana (Vyāsa))

(proper noun)

Nominative, masculine, singular of dvaipāyana

dvaipāyana - Dvaipāyana (an epithet of Vyāsa, meaning 'island-born')

From dvīpa (island) + suffix āyana

Note: Refers to Vyāsa.

अब्रवीत् (abravīt) - he said, he spoke

(verb)

3rd person , singular, active, imperfect (laṅ) of brū

Imperfect Active

Root brū (class 2), imperfect 3rd singular with augment 'a'

Root: brū (class 2)