Vaishampayana said, "Cursed by the intelligent Vishvamitra in anger, Sarasvati, in that auspicious and best of tirthas, flowed, bearing blood in her current. Then, O king, many Rakshasas came, O Bharata, and lived happily there, drinking the blood that flowed. Exceedingly gratified with that blood, cheerfully and without anxiety of any kind, they danced and laughed there like persons that have (by merit) attained to heaven. After some time had passed away, some Rishis, possessed of wealth of asceticism, came to the Sarasvati, O king, on a sojourn to her tirthas. Those foremost of Munis, having bathed in all the tirthas and obtained great happiness, became desirous of acquiring more merit. Those learned persons at last came, O king, to that tirtha where the Sarasvati ran a bloody current. Those highly blessed ones, arriving at that frightful tirtha, saw the water of the Sarasvati mixed with blood and that innumerable Rakshasas, O monarch, were drinking it. Beholding those Rakshasas, O king, those ascetics of rigid vows made great endeavours for rescuing the Sarasvati from that plight. Those blessed ones of high vows, arrived there, invoked that foremost of rivers and said these words unto her, 'Tell us the reason, O auspicious lady, why this lake in thee hath been afflicted with such distress Hearing it, we shall endeavour (to restore it to its proper condition).' Thus questioned, Sarasvati, trembling as she spoke, informed them of everything that had occurred. Seeing her afflicted with woe, those ascetics said, 'We have heard the reason. We have heard of thy curse, O sinless lady! All of us shall exert ourselves!' Having said these words unto that foremost of rivers, they then consulted with one another thus, 'All of us shall emancipate Sarasvati from her curse.' Then all those Brahmanas, O king, worshipping Mahadeva, that lord of the universe and protector of all creatures, with penance and vows and fasts and diverse kinds of abstinences and painful observances, emancipated that foremost of rivers, the divine Sarasvati. Beholding the water of Sarasvati purified by those Munis, the Rakshasas (that had taken up their abode there), afflicted with hunger, sought the protection of those Munis themselves. Afflicted with hunger, the Rakshasas, with joined hands, repeatedly said unto those ascetics filled with compassion, these words, 'All of us are hungry! We have swerved from eternal virtue! That we are sinful in behaviour is not of our free will! Through the absence of your, grace and through our own evil acts, as also through the sexual sins of our women, our demerits increase and we have become Brahma-Rakshasas! So amongst Vaisyas and Sudras, and Kshatriyas, those that hate and injure Brahmanas became Rakshasas. Ye best of Brahmanas, make arrangements then for our relief! Ye are competent to relieve all the worlds!' Hearing these words of theirs, those ascetics praised the great river. For the rescue of those Rakshasas, with rapt minds those ascetics said, 'The food over which one sneezed, that in which there are worms and insects, that which may be mixed with any leavings of dishes, that which is mixed with hair, that which is mixed with tears, that which is trodden upon shall form the portion of these Rakshasas! The learned man, knowing all this, shall carefully avoid these kinds of food. He that shall take such food shall be regarded as eating the food of Rakshasas!' Having purified the tirtha in this way, those ascetics thus solicited that river for the relief of those Rakshasas. Understanding the views of those great Rishis, that foremost of rivers caused her body, O bull among men, to assume a new shape called Aruna. Bathing in that new river (a branch of the Sarasvati) the Rakshasas cast off their bodies and went to heaven. Ascertaining all this, the chief of the celestials, (Indra of a hundred sacrifices), bathed in that foremost of tirthas and became cleansed of a grievous sin."
Janamejaya said, "For what reason was Indra tainted with the sin of Brahmanicide? How also did he become cleansed by bathing in that tirtha?"
Vaishampayana said, "Listen to that history, O ruler of men! Hear of those occurrences as they happened! Hear how Vasava, in days of yore, broke his treaty with Namuchi! The Asura Namuchi, from fear of Vasava, had entered a ray of the Sun. Indra then made friends with Namuchi and entered into a covenant with him, saying, 'O foremost of Asuras, I shall not slay thee, O friend, with anything that is wet or with anything that is dry! I shall not slay thee in the night or in the day! I swear this to thee by truth. Having made this covenant, the lord Indra one day beheld a fog. He then, O king, cut off Namuchi's head, using the foam of water (as his weapon). The severed head of Namuchi thereupon pursued Indra from behind, saying unto him from a near point these words, 'O slayer of a friend, O wretch!' Urged on incessantly by that head, Indra repaired to the Grandsire and informed him, in grief, of what had occurred. The Supreme Lord of the universe said unto him, 'Performing a sacrifice, bathe with due rites, O chief of the celestials, in Aruna, that tirtha which saveth from the fear of sin! The water of that river, O Shakra, hath been made sacred by the Munis! Formerly the presence of that river at its site was concealed. The divine Sarasvati repaired to the Aruna, and flooded it with her waters. This confluence of Sarasvati and Aruna is highly sacred! Thither, O chief of the celestials, perform a sacrifice! Give away gifts in profusion! Performing thy ablutions there, thou shall be freed from thy sin.' Thus addressed, Shakra, at these words of Brahma, O Janamejaya, performed in that abode of Sarasvati diverse sacrifices. Giving away many gifts and bathing in that tirtha, he of a hundred sacrifices, the piercer of Vala, duly performed certain sacrifices and then plunged in the Aruna. He became freed from the sin arising out of the slaughter of a Brahmana. The lord of heaven then returned to heaven with a joyful heart. The head of Namuchi also fell into that stream, O Bharata, and the Asura obtained many eternal regions, O best of kings, that granted every wish."
Vaishampayana continued, "The high-souled Baladeva having bathed in that tirtha and given away many kinds of gifts, obtained great merit. Of righteous deeds, he then proceeded to the great tirtha of Soma. There, in days of yore, Soma himself, O king of kings, had performed the Rajasuya sacrifice. The high-souled Atri, that foremost of Brahmanas, gifted with great intelligence became the Hotri in that grand sacrifice. Upon the conclusion of that sacrifice, a great battle took place between the gods (on the one side) and the Danavas, the Daityas, and the Rakshasas (on the other). That fierce battle is known after the name of (the Asura) Taraka. In that battle Skanda slew Taraka. There, on that occasion, Mahasena (Skanda), that destroyer of Daityas, obtained the command of the celestial forces. In that tirtha is a gigantic Aswattha tree. Under its shade, Kartikeya, otherwise called Kumara, always resides in person."