Adi Parva - Astika Parva 41

"Saunaka asked, 'What great Rishis became the Ritwiks at the
snake-sacrifice of the wise king Janamejaya of the Pandava line? Who also
became the Sadasyas in that terrible snake-sacrifice, so frightful to the
snakes, and begetting such sorrow in them? It behoveth thee to describe
all these in detail, so that, O son of Suta, we may know who were
acquainted with the rituals of the snake-sacrifice.'

"Sauti replied, 'I will recite the names of those wise ones who became
the monarch's Ritwiks and Sadasyas. The Brahmana Chandabhargava became
the Hotri in that sacrifice. He was of great reputation, and was born in
the race of Chyavana and was the foremost of those acquainted with the
Vedas. The learned old Brahmana, Kautsa, became the Udgatri, the chanter
of the Vedic hymns. Jaimini became the Brahmana, and Sarngarva and
Pingala the Adhvaryus, Vyasa with his son and disciples, and Uddalaka,
Pramataka, Swetaketu, Pingala, Asita, Devala, Narada, Parvata, Atreya,
Kundajathara, the Brahmana Kalaghata, Vatsya, old Srutasravas ever
engaged in japa and the study of the Vedas. Kohala Devasarman, Maudgalya,
Samasaurava, and many other Brahmanas who had got through the Vedas
became the Sadasyas at that sacrifice of the son of Parikshit.

"When the Ritwiks in that snake-sacrifice began to pour clarified butter
into the fire, terrible snakes, striking fear into every creature, began
to fall into it. And the fat and the marrow of the snakes thus falling
into the fire began to flow in rivers. And the atmosphere was filled with
an insufferable stench owing to the incessant burning of the snakes. And
incessant also were the cries of the snakes fallen into the fire and
those in the air about to fall into it.

'Meanwhile, Takshaka, that prince of snakes, as soon as he heard that
king Janamejaya was engaged in the sacrifice, went to the palace of
Purandara (Indra). And that best of snakes, having represented all that
had taken place, sought in terror the protection of Indra after having
acknowledged his fault. And Indra, gratified, told him, 'O prince of
snakes, O Takshaka, here thou hast no fear from that snake-sacrifice. The
Grandsire was pacified by me for thy sake. Therefore, thou hast no fear.
Let this fear of thy heart be allayed.'

Sauti continued, 'Thus encouraged by him, that best of snakes began to
dwell in Indra's abode in joy and happiness. But Vasuki, seeing that the
snakes were incessantly falling into the fire and that his family was
reduced to only a few, became exceedingly sorry. And the king of the
snakes was afflicted with great grief, and his heart was about to break.
And summoning his sister, he spake unto her, saying, 'O amiable one, my
limbs are burning and I no longer see the points of the heavens. I am
about to fall down from loss of consciousness. My mind is turning, my
sight is falling and my heart is breaking. Benumbed, I may fall today
into that blazing fire! This sacrifice of the son of Parikshit is for the
extermination of our race. It is evident I also shall have to go to the
abode of the king of the dead. The time is come, O my sister, on account
of which thou wert bestowed by me on Jaratkaru to protect us with our
relatives. O best of the women of the snake race, Astika will put an end
to the sacrifice that is going on. The Grandsire told me this of old.
Therefore, O child, solicit thy dear son who is fully conversant with the
Vedas and regarded even by the old, for the protection of myself and also
of those dependent on me."'