Mahabharata 1.6.2

1.6.2

tataḥ sa garbho nivasankukṣau bhṛgukulodvaha |
roṣānmātuścyutaḥ kukṣeścyavanastena so'bhavat || 2 ||

"Sauti said, 'O Brahmana, having heard these words from the god of fire, the Rakshasa assumed the form of a boar, and seizing the lady carried her away with the speed of the wind--even of thought. Then the child of Bhrigu lying in her body enraged at such violence, dropped from his mother's womb, for which he obtained the name of Chyavana. And the [paragraph continues] Rakshasa perceiving the infant drop from the mother's womb, shining like the sun, quitted his grasp of the woman, fell down and was instantly converted into ashes. And the beautiful Pauloma, distracted with grief, O Brahmana of the Bhrigu race, took up her offspring Chyavana, the son of Bhrigu and walked away. And Brahma, the Grandfather of all, himself saw her, the faultless wife of his son, weeping. And the Grandfather of all comforted her who was attached to her son. And the drops of tears which rolled down her eyes formed a great river. And that river began to follow the foot-steps of the wife of the great ascetic Bhrigu. And the Grandfather of the worlds seeing that river follow the path of his son's wife gave it a name himself, and he called it Vadhusara. And it passeth by the hermitage of Chyavana. And in this manner was born Chyavana of great ascetic power, the son of Bhrigu.