Brahmarshi Vishvamitra (viśvā-mitra) is one of the most venerated rishis or sages of ancient India. He is also credited as the author of most of Mandala 3 of the Rigveda, including Gayatri Mantra. The Puranas mention that only 24 rishis since antiquity have understood the whole meaning of—and thus wielded the whole power of—Gayatri Mantra. Vishvamitra is supposed to be the first, and Yajnavalkya the last. The story of Vishvamitra is narrated in the Balakanda of Valmiki Ramayana. Mahabharata adds that Vishvamitra's relationship with Menaka resulted in a daughter, Shakuntala, whose story is narrated in Adi Parva of Mahabharata.