To which deity is the Gayatri Mantra addressed? What exactly does it mean or signify? Why should we chant the Gayatri Mantra ?
Swami Chinmayananda in his book Meditation and Life, Chapter 18 writes,
This mantra is dedicated to the Lord Savitṛ . That Savitṛ represents Lord Sun is the accepted version, although some scholars protest against this interpretation. The sun gives all illumination to the world, and any prayer for light should certainly be addressed to the source of all light in the material world – the sun. In the Bhagavad-gītā Lord Kṛṣṇa says, “The light that pervades the sun and the moon is all My light.” Thus, Savitr, the Lord of Gāyatrī, is nothing other than the Light of Consciousness, the Infinite, the Absolute. ‘We meditate upon the auspicious, godly light of the Lord Sun. May that heavenly light illumine the thought flow in our intellect’. In our own inner life, the sun represents the illuminator of all experiences, the Ᾱtman. This pure Consciousness in us, around which the matter envelopments function – just as the entire solar system revolves around the sun – is being invoked to shine more fully in our intellect. If the sun were not there, physical life on earth would be impossible. Without Ᾱtman, the matter envelopments would become inert. In chanting the Gāyatrī mantra, the devotee is actually praying for spiritual unfoldment – ‘May my intellect be steady without agitations; may it be clean without the dirt of passions. May the light of Consciousness come to shine forth its radiance through my intellect. Thus, may my perception of the world be clear, my discrimination subtle, my judgements correct and quick, my comprehension of situations precise and wise’.
He continues to explain the reason, why to chant Gayatri Mantra,
The Taittirīya Ᾱraṇyaka explains in story form the reason for the daily chanting of the Gāyatrī and the offering poured toward the sun. On an island called Arunam lived a tribe of devils called Mandehas. Every morning these devils conquered all space and almost reached the sun, threatening to destroy him. But the water thrown by the Gāyatrī japists was lightning-strong striking the devils and forcing them to retreat to their islands. The story is symbolic of events in one’s mind. Mind (manas) and body (deha) are the sources of our activities. With their likes, dislikes, emotions, appetites, passions, and cravings, they bring out our passionate animal instincts, which try to conquer and destroy the spiritual essence – Brahman or the sun – in us. The essential brilliance of the human intellect is clouded by these passions. The Gāyatrī japa, with the force of lightning, descends upon them and dissipates them.