What is the meaning of Gayatri Mantra?
ॐ भूर्भुव: स्व: तत्सवितुर्वरेण्यं । भर्गो देवस्य धीमहि, धीयो यो न: प्रचोदयात् ।।
The English translation of Rigveda 3.62.10 is as follows:
तत्सवितुर्वरेण्यं भर्गो देवस्य धीमहि।
धियो यो नः प्रचोदयात्॥ ३.०६२.१०
May we attain that excellent glory of Savitar the God: So May he stimulate our prayers.
Knowing the literal meaning only would not help in understanding the Gayatri Mantra. So, some explanation for it would be useful. Actually the translation or commentary given by Acharyas would be the best source to understand. I think it would be worthy to quote the explanation from Gayatri Pariwara. You can read some articles on Gayatri and on Gayatri Mantra.
ॐ भूर्भुवः स्वः तत्सवितुर्वरेण्यं भर्गो देवस्य धीमहि धियो यो नः प्रचोदयात्।
उस प्राणस्वरूप, दुःखनाशक, सुखस्वरूप, श्रेष्ठ, तेजस्वी, पापनाशक, देवस्वरूप परमात्मा को हम अन्तःकरण में धारण करें। वह परमात्मा हमारी बुद्धि को सन्मार्ग में प्रेरित करे।
Here is one explanation given by them:
Om bhurbhuvah swah tatsaviturvarenyam bhargo devasya dhimahi dhiyo yo nah prachodayat
Om Brahma or Almighty God Bhuh embodiment of vital spiritual energy (Prana) bhuvah destroyer of sufferings swah embodiment of happiness tat that savituh bright, luminous like the Sun varenyam best, most exalted bhargo destroyer of sins devasya divine dhimahi may imbibe dhiyo intellect yo who nah our prachodayat may inspire
Here is a detailed explanation given for the purpose of meditation:
In short it is a prayer to the Almighty Supreme God, the Creator of entire cosmos, the essence of our life existence, who removes all our pains and sufferings and grants happiness beseeching His divine grace to imbibe within us His Divinity and Brilliance which may purify us and guide our righteous wisdom on the right path.
A man gets imbued with divine qualities contemplating and meditating on this meaning of Gayatri. One should contemplate on these feelings daily and regularly. Three prayer-filled meditations are given here which should be silently recited and projected on the mental screen through imagination.
“The Almighty God, who is known as pranava pervades all the three Lokas, viz, Bhooh-loka, Bhuvah-loka and Swaha-loka. He is Omnipresent. The cosmos is physical manifestation of God who pervades its each and every particle. I am seeing Him everywhere. I would always refrain from evil thoughts and evil deeds and perform true worship of God by extending cooperation in promoting happiness, peace and beauty in this universe which is His creation”.
“This (tat) God is extremely bright (savitur), most exalted (varenyam), devoid of sin (bhargo) and divine (devasya). I visualize this Divinity within me, in my soul. By such contemplation, I am becoming illumined, virtues are growing in all the layers of my being. I am being saturated with these virtues, these characteristics, of God.”
“That God may inspire (prachodayat) our (naha) intellect, wisdom (dhiyo) and lead us on righteous path. May our intellect, the intellects of our family members and of all of us, be purified and may He lead us on the righteous path. On getting righteous wisdom, which is the greatest achievement and is the source of all the happiness in this world, we may be able to enjoy celestial bliss in this life and make our human life purposeful.”
We should contemplate and meditate on these three prayer-filled meditations slowly and pausing for a moment on each word and an imaginary picture of that word should be drawn in the mind.
They have also given detailed explanation according to the Sadhana point of view; you can refer this article.
And finally the article on Knowledge in Gayatri Mantra provides subtle meaning and explanation to the every terms of Gayatri Mantra.
Click on the respective links of terms of Gayatri Mantra; They have provided Sanskrit Sloka with meaning and explanation for every terms. (I think as a Gayatri Geeta).
Tat savitur varenyam (1)
Bhargo devasya dhimahi (2)
Dhiyo yo nah prachodayAt (3)||
We meditate on the excellent splendour (bhargo) of the Divine Savitr (2), who is supremely desirable (varenya) and is That One (tat) (1). May he activate our thoughts towards wisdom (3).
Rig Veda 3.62.10
The above translation is from the Sri Aurobindo-KApaly ShAstry school and found in the book called "Rig Veda Mandala 3", by R.L.Kashyap.
The same mantra appears in VAjasaneyi Samhita (VS) 3.35, and in Tattriya SamhitA too. In these cases the "Om Bhur Bhuvah Swaha" part is not present.
The mantra accompanied with the four aforementioned syllables appears in VS 36.3 (of the Shukla Yajurveda) and also in the Krishna Yajur Veda.
And, the meaning is simply:
Om Bhur Bhuvah Swah.
Om Earth, Mid-world, Heaven.
Om, in it's crudest form means I.
Bhur is earth or Human Body. Bhuvah refers to the life-force, which makes the body vibrate. Swah refers to Prajnāna-shakti, which sustains the life-force. This Prajnāna-shakti is known as constant integrated awareness. This is also termed as radiation. All three, namely, materialization, vibration and radiation are present in man.
Same mantra can also be found in Yajurveda Samhita Adhyay 36, Mantra 3 , but without Om i.e. Pranavakshara"
भूर्भुव: स्व: तत्सवितुर्वरेण्यं । भर्गो देवस्य धीमहि, धीयो यो न: प्रचोदयात्।
BHOOR BHUWAH SWAHA TAT SAVITUR VARENYAM BHARGO DEVASAYA DHEEMAHI DHIYO YO NAHA PRACHODAYAT
We meditate on the Paramatma (Supreme Soul) who is Prana Swaroop (life force) , glorious , who is remover of miseries , who is shining bright , almighty , and who is bestower of the divine qualities. May he take our intellect onto the path of righteousness.
There can be as many meanings of mantras as there are seekers of whatever the reciter of the mantra is seeking. As the saying in Sanskrit goes, 'Manasa trayate iti mantra'. What is churned through the mind is called mantra. So meaning of mantra is what is sought through the repeated and unceasing recital of the mantra. Such a recital is no different from meditation on a thought without recital of mantra with bodily speech or even mental speech. Actions with body, speech and mind are progressively better actions; such as, the ritual worship of an idol, the reciting of mantra or name of the Lord and the meditation on single thought in mind. Better than ritual worship with loud chanting is softer chanting in the mind; and even better than that is the concentration of the mind on a single thought.
Upasakas (worshippers in mind) of consciousness per se, as the best light shining in the mind, is comparable to meditation on gayatri mantra. In that sense in plain Sanskrit language the meaning of the gayatri mantra will be - best sun (bhargo deva) like light, the best light of deva savita (name of essence like spirit), may that light shine in my intellect. In this view the mantra is only an allegorical help to meditate on super-consciousness as the Lord who shines as the mind of human beings.