Sandhya Vidhi is explained in various Puranas especially Agni Purana, Padma Purana, Bhavishya Purana and Narada Purana. This seeks to optimise (‘Nyasa’) of the integration of the body, the inner Soul and the Supreme Force. In the human body there are ten important veins which create Prana Vayu viz. Ida, Pingala, Sushumna, Gandhari, Hastijihva, Prutha, Yasha, Alambusha, Huhu, and Shankhini. Apart from Prana Vaayu, there are nine other forms of breathing viz. Vyana, Apaana,, Samaana, Udaana, Naga, Kurma, Krikara, Devadutta, and Dhananjaya. Most importantly, there are Five forms of Life’s breathing process which are of utmost importance: Prana (The Principal Energy), Apaana (Internal Energy), Samaana (the Balancing Energy), Vyaana or the Central Energy, and Udaana (the External Energy). Thus Devi Gayatri is stated to possess Five Faces representing Five Portions of the Sacred Gayatri Mantra: OM (the Central Face)-BHURBHUVASSASAHAH (the Second Face)- TAT SAVITUR VARENYAM ( the Third Face)-BHARGO DEVASYA DHIMAHI (the Fourth  Face) –and DHIYO YONAH  PRACHODAYAT (the Fifth Face). The Trimurtis Brahma (the Creator),Vishnu (the Sustainer) and Maheswara (the Liquidator) with the three Gunas or Attributes are together absorbed in the Prayer to Devi Gayatri;  integration of the human body who renders the Mantra and Paramatma takes place instantly via the Three Murtis and the best conduit is the Gayatri Mantra. The literal meaning of the Gayatri is: Om                        (Hey Paramatma!); Bhur (the Embodiment of Vital Energy), Bhuvaha (the Destroyer of Sufferings), Swaha (the Form of Hapoiness),Tat ( that God), Savitur (Bright like Sun), Varenyam (The Magnificent), Bhargo (the Destroyer  of Sins), Devasya (The Divine Force), Dhimahi ( May Receive), Dhiyo (Intellect), Yo (who), Na ( our), Prachodayaat ( let it be inspired in the right direction); In sum  the meaning states: Oh God, Yor are the Creator of Life, the Destroyer of Sorrow, the Bestower of Happiness and the Creator of the Universe; may we  receive your Supreme Light to demolish our sins and guide us in our intellect in the right direction)!’

[Scientific explanations were offered by modern Scientists about the Gayatri Mantra. According to Astro Physics and Astronomy, a sound is produced due to the fast movement of Bhumi, the Planets and the Galaxy or the Milky Way, called Akshaya Ganga having some 100,000 million Stars. The Galaxy, the Moon and the Earth-all revolving around Sun-each moving on their own axis at a mind boggling velocity speed of 20,000 miles per second produce a Super Sound and Rishis named it as OM. The sum of Gayatri is as follows: The Earth (Bhur), the Planets (Bhuvaha) and the Galaxy (Swahah) are rotating on their axis at a great velocity as a Unique Sound is made which was a Formless Entity. The total Kinetic Energy generated by the movement totalled or balanced the total Energy consumption of Cosmos and this was named as Pranava or the Body Energy (mass of Galaxy multiplied by velocity and further multiplied by two: Mass x Velocity x 2). That Entity (God) who manifested in the Form of Radiance (Sun or Savitur) is worthy of bowing or of reverence. We should meditate (dheemahi) upon the light (bhargo) of that Entity (Devasya) as also perform the chanting of OM. May he (Yo) guide us in the right Direction (Prachodayaat) our intellect (dhiyo)!] Chanting the Gayatri Mantra by understanding the meaning and purport even a few times a day would demolish sins and the more number of times one recited would secure multiplied fruits.