Shloka 31

अरुणायां महाराज ब्रद्मावध्यापहा हि सा । नरश्रेष्ठ! महर्षियोंका यह मत जानकर सरिताओंमें श्रेष्ठ सरस्वती अपनी ही स्वरूपभूता अरुणाको ले आयी। महाराज! उस अरुणामें स्नान करके वे राक्षस अपना शरीर छोड़कर स्वर्गलोकमें चले गये; क्योंकि वह ब्रह्महत्याका निवारण करनेवाली है || २९-३० $ ।। एतमर्थमभिज्ञाय देवराज: शतक्रतु:ः

aruṇāyāṃ mahārāja brahmāvadhyāpahā hi sā | naraśreṣṭha mahārṣīṇāṃ etan mataṃ jñātvā saritāṃ śreṣṭhā sarasvatī svāṃ svarūpabhūtām aruṇāṃ ānayat | mahārāja tasyām aruṇāyāṃ snātvā te rākṣasāḥ śarīraṃ tyaktvā svargalokaṃ jagmuḥ, yasmāt sā brahmahatyā-nivāriṇī || etam artham abhijñāya devarājaḥ śatakratuḥ ||

Vaiśaṃpāyana said: “O king, Aruṇā is indeed a remover of the taint of brahma-slaughter. O best of men, understanding this conviction of the great seers, Sarasvatī—foremost among rivers—brought forth Aruṇā, who is of her own very essence. O king, after bathing in that Aruṇā, those rākṣasas cast off their bodies and went to heaven, for she has the power to annul the sin of brahmahatyā.” Having understood this matter, the lord of the gods, Śatakratu (Indra)…

{'aruṇāyām''in/at the river Aruṇā (locative singular)', 'mahārāja': 'O great king (vocative)', 'brahmahatyā': 'the sin of killing a brāhmaṇa
{'aruṇāyām':
‘brahma-slaughter’', 'apahā / apahāriṇī''removing, taking away, dispelling', 'naraśreṣṭha': 'O best of men', 'mahārṣi': 'great seer, eminent ṛṣi', 'mata': 'view, settled opinion, doctrine', 'saritām śreṣṭhā': 'best among rivers', 'sarasvatī': 'the river-goddess Sarasvatī', 'svarūpabhūtā': 'constituting one’s own essence
‘brahma-slaughter’', 'apahā / apahāriṇī':
of the same essential nature', 'ānayat''brought, led, produced', 'snātvā': 'having bathed', 'rākṣasāḥ': 'rākṣasas (a class of powerful beings, often hostile/demonic)', 'śarīraṃ tyaktvā': 'having abandoned the body', 'svargaloka': 'the heavenly world', 'nivāriṇī': 'one who wards off, averts, removes', 'etam artham abhijñāya': 'having understood this matter/meaning', 'devarāja': 'king of the gods', 'śatakratu': '‘performer of a hundred sacrifices’, epithet of Indra'}
of the same essential nature', 'ānayat':

वैशम्पायन उवाच

V
Vaiśaṃpāyana
A
Aruṇā (river)
S
Sarasvatī (river-goddess)
M
Mahārṣis (great seers)
R
Rākṣasas
S
Svarga (heaven)
I
Indra (Śatakratu, Devarāja)
B
Brahmahatyā (sin/taint)

Educational Q&A

The passage emphasizes the ethical idea that grave moral taints (like brahmahatyā) require purification and expiation, and that sacred tīrthas—understood as embodiments of divine power—are portrayed as capable of restoring moral and spiritual purity, enabling even deeply fallen beings to attain a higher state.

Vaiśaṃpāyana explains that the river Aruṇā, brought forth by Sarasvatī after the seers’ counsel, has the power to remove the sin of brahmahatyā. Certain rākṣasas bathe in Aruṇā, abandon their bodies, and reach heaven. The verse then transitions to Indra (Śatakratu) reacting upon learning this.