Gāyatrī Mantra

The Gāyatrī Mantra is often also called the ‘Great Mantra’ (‘Mahā Mantra’); it is considered the essence of the Vedas.  Chanting this mantra is a way of cultivating intuitive awareness and wisdom.

O bhūr bhuvaḥ svaḥ;
Tat Savitur vareṇya,
bhargo devasya dhīmahi,
dhiyo yo naḥ prachodayāt.

O God; O Earth, Sky and Heaven;
That Savitaḥ (‘The Essence of Light‘: Sun/God) – the destroyer of ignorance – who is to be followed,
I meditate on His energy,
may He awaken my mind.

It is important to chant the mantra with mindfulness, while focusing on the deeper meaning of the words. Generally the mantra is chanted three times a day (morning, afternoon, evening), though it also perfectly possible to chant it at any other given time. One may chant the mantra 3, 9, 18 or 108 times.

Reference:

Keshavadas, Sadguru Sant, 2000: ‘Gāyatrī: The Highest Meditation‘. Delhi: Motilal Banarsidass Publishers; p. 2.