Mbh 12.365.4

"'Bhishma said, "Having saluted that foremost of Nagas in this way, the Brahmana (named Dharmaranya), firmly resolved to follow the Unccha mode of life, proceeded to the presence, O king, of Chyavana of Bhrigu's race, from desire of being formally instructed and initiated in that vow.[1942] Chyavana performed the Samskara rites of the Brahmana and formally initiated him into the Unccha mode of life. The son of Bhrigu, O monarch, recited this history to king Janaka in his place. King Janaka, in his turn, narrated it to the celestial Rishi Narada of high soul. The celestial Rishi Narada too, of stainless acts, repairing on one occasion to the abode of Indra, the chief of the deities, gave to Indra this history upon being asked by him. The chief of the celestials, having obtained it thus from Narada, recited this blessed history to a conclave consisting of all the foremost Brahmanas, O monarch. On the occasion, again, of my dreadful encounter with Rama of Bhrigu's race (on the field of Kurukshetra), the celestial Vasus, O king, recited this history to me.[1943] Asked by thee, O foremost of righteous men, I have recited this history that is excellent and sacred and fraught with great merit. Thou hadst asked me about what constitutes the highest duty, O king. This history is my answer to thy query. A brave man he was, O monarch, that betook himself to the practice of the Unccha vow in this way, without expectation of any fruit. Firmly resolved, that Brahmana, instructed, by the chief of Nagas in this way about his duty, betook himself to the practice of Yama and Niyama, and subsisting the while upon such food as was allowed by the Unccha vow, proceeded to another forest."'"