The Gāyatrī Mantra, also known as the Sāvitrī mantra, is a highly revered mantra from the Rig Veda (Mandala 3.62.10), dedicated to Savitr, the Sun deity. Gāyatrī is the name of the Vedic meter in which the verse is composed. Its recitation is traditionally preceded by oṃ and the formula bhūr bhuvaḥ svaḥ, known as the mahāvyāhṛti, or "great (mystical) utterance".
The Gayatri mantra is cited widely in Vedic and post-Vedic texts, such as the mantra listings of the Śrauta liturgy, and classical Hindu texts such as the Bhagavad Gita,Harivamsa, and Manusmṛti. It is the subject of esoteric treatment and explanation in some major Upanishads, and is also referred to in the Buddhist Pali Canon.
The mantra is an important part of the upanayana ceremony for young males in Hinduism, and has long been recited by dvija men as part of their daily rituals. Modern Hindu reform movements spread the practice of the mantra to include women and all castes and its use is now very widespread.
The main mantra appears in the hymn RV 3.62.10. During its recitation, the hymn is preceded by oṃ (ॐ) and the formula bhūr bhuvaḥ svaḥ (भूर् भुवः स्वः). This prefixing of the mantra proper is described in the Taittiriya Aranyaka (2.11.1-8), which states that it should be chanted with the syllable oṃ, followed by the three Vyahrtis and the Gayatri verse. Whereas in principle the gāyatrī mantra specifies three pādas of eight syllables each, the text of the verse as preserved in the Samhita is one short, seven instead of eight. Metrical restoration would emend the attested tri-syllabic vareṇyaṃ with a tetra-syllabic vareṇiyaṃ.