Mahabharata Anushasna Parva Chapter 4:3

Mahabharata Anushasna Parva (Dana Dharma Parva) Chapter 4:3 Do thou confer this favour on me.'—'Be it so,'—said that man of austere penances to his wife and then, O king, she gave birth to a blessed son named Jamadagni. The celebrated wife of Gadhi too gave birth to the regenerate Rishi Viswamitra versed in the knowledge of Brahma, by favour of that Rishi. The highly devout Viswamitra, though a Kshatriya, attained to the state of a Brahmana and became the founder of a race of Brahmanas. His sons became high-souled progenitors of many races of Brahmanas who were devoted to austere penances, learned in the Vedas, and founders of many clans. The adorable Madhuchcchanda and the mighty Devrat, Akshina, Sakunta, Vabhru, Kalapatha, the celebrated Yajnavalkya, Sthula of high vows, Uluka, Mudgala, and the sage Saindhavayana, the illustrious Valgujangha and the great Rishi Galeva, Ruchi, the celebrated Vajra, as also Salankayana, Liladhya and Narada, the one known as Kurchamuka, and Vahuli, Mushala, as also Vakshogriva, Anghrika, Naikadrik, Silayupa, Sita, Suchi, Chakraka, Marrutantavya, Vataghna, Aswalayana, and Syamayana, Gargya, and Javali, as also Susruta, Karishi, Sangsrutya, and Para Paurava, and Tantu, the great sage Kapila, Tarakayana, Upagahana, Asurayani, Margama, Hiranyksha, Janghari, Bhavravayani, and Suti, Bibhuti, Suta, Surakrit, Arani, Nachika, Champeya, Ujjayana, Navatantu, Vakanakha, Sayanya, Yati, Ambhoruha, Amatsyasin, Srishin, Gardhavi Urjjayoni, Rudapekahin, and the great Rishi Naradin,—these Munis were all sons of Viswamitra and were versed in the knowledge of Brahma. O king Yudhishthira, the highly austere and devout Viswamitra, although a Kshatriya (by descent), became a Brahmana for Richika having placed the energy of supreme Brahma (in the charu). O foremost prince of Bharata's race, I have now related to you, with all details, the story of the birth of Viswamitra who was possessed of energy of the sun, the moon, and the fire-god. O best of kings, if thou hast any doubt with regard to any other matter, do thou let me know it, so that I may remove it.