The Mahabharata/Book 1: Adi Parva/Section XV
"Sauti said, 'O foremost of persons acquainted with Brahma, the mother of the snakes had cursed them of old, saying, 'He that hath the Wind for his charioteer (viz., Agni) shall burn you all in Janamejaya's sacrifice!'
It was to neutralise that curse that the chief of the snakes married his sister to that high-souled Rishi of excellent vows. The Rishi wedded her according to the rites ordained (in the scriptures), and from them was born a high-souled son called Astika. An illustrious ascetic; versed in the Vedas and their branches, he regarded all with an even eye, and removed the fears of both his parents.
"Then, after a long space of time, a king descending from the Pandava line celebrated a great sacrifice known as the Snake-sacrifice, After that sacrifice had commenced for the destruction of the snakes, Astika delivered the Nagas, viz., his brothers and maternal uncles and other snakes (from a fiery death). And he delivered his fathers also by begetting offspring. And by his austerities, O Brahmana, and various vows and study of the Vedas, he freed himself from all his debts. By sacrifices, at which various kinds of offerings were made, he propitiated the gods. By practising the Brahmacharya mode of life he conciliated the Rishis; and by begetting offspring he gratified his ancestors.
"Thus Jaratkaru of rigid vows discharged the heavy debt he owed to his sires who being thus relieved from bondage ascended to heaven. Thus having acquired great religious merit, Jaratkaru, after a long course of years, went to heaven, leaving Astika behind. There is the story of Astika that I have related duly Now, tell me, O tiger of Bhrigu's race, what else I shall narrate."
So ends the fifteenth section in the Astika Parva of the Adi Parva.