(c) The earliest occurrence of the mantra famous as Gayatri Mantra is found in the Rig Veda. Gayatri Mantra comes from the 3rd Mandal of the Rig Veda. This mandal has 62 hymns, mainly to Agni and Indra.It is one of the family books(mandal 2 to 7), the oldest core of the Rig Veda.