The Gāyatrī Mantra is a highly revered mantra, based on a Vedic Sanskrit verse from a hymn of the Rigveda (3.62.10), attributed to the rishi Viśvāmitra. The mantra is named for its vedic gāyatrī metre. As the verse invokes the deva Savitr, it is also called Sāvitrī. Its recitation is traditionally preceded by oṃ and the formula bhūr bhuvaḥ svaḥ, known as the mahāvyāhṛti ("great utterance").