Aum is the most sacred sound by which innumerable souls have found out their origin or source. The sound Aum is having it’s own vibration with which we are able to transcend into the higher dimensions quite easily. The three sounds of ‘Aum’ denotes the three worlds, like the maierial world is won over by the first sound when we start chanting the sacred syllable, the second word if concentrated gives a mind supremacy over heaven and moon. When all the three are meditated upon, it makes the person united with the sun. The silence but at the end of this mantra is the most sacred and this is the turiya or the fourth state where the mind becomes still between thoughts and this is verily Brahman or the supreme power.
The supreme consciousness is if I have to give a very simple explanation, that state which you have sometimes as a fleeting glimpse; when a thought leaved your mind and before the next thought comes a strange peaceful state prevails. Next time feel it… as may be for a long time, you may be able to enjoy these fortunate movements of realization only, even if you start serious seeking now!!!
“The goal which all the Vedas declare, which all austerities aim at, and which men desire when they lead the life of continence, I will tell you briefly: it is Om. This syllable Om is indeed Brahman. This syllable is the Highest. Whosoever knows this syllable obtains all that he desires. This is the best support; this is the highest support. Whosoever knows this support is adored in the world of Brahma.” (Yama saya this to Nachiketas in Katha Upanishad)
“Take the Upanishad as the bow, the great weapon, and place upon it the arrow sharpened by meditation. Then, having drawn it back with a mind directed to the thought of Brahman, strike that mark, O my good friend-that which is the Imperishable Om is the bow; the atman is the arrow; Brahman is said to be the mark. It is to be struck by an undistracted mind. Then the atman becomes one with Brahman, as the arrow with the target.” (Mundaka Upanishad) “
The syllable AUM is the Supreme Brahman and also the other Brahman. Therefore he who knows it attains, with its support, the one or the other. If he meditates on one letter (matra), then, being enlightened by that alone, he quickly comes back to earth after death. The rik verses lead him to the world of men. By practising austerity, chastity, and faith he enjoys greatness. If, again, he meditates on the second letter, he attains the mind and is led up by the yajur verses to the intermediate space, to the Plane of the Moon. Having enjoyed greatness in the Plane of the Moon, he returns hither again. Again, he who meditates on the Highest Person through this syllable AUM consisting of three letters, becomes united with the effulgent Sun.
“As a snake is freed from its skin, even so he is freed from sin. The three letters of AUM are mortal; but when joined together in meditation on the total Reality and used properly on the activities of the external, internal, and intermediate states, the knower trembles not. The wise man, meditating on AUM, attains this world by means of the rik verses; the intermediate world by means of the yajur verses; and that which is known to the seers by means of the sama verses. And also through the syllable AUM he realises that which is tranquil, free from decay, death, and fear, and which is the Highest.” (Sage Pippalada To Satyakama in Prasna Upanishad)
Given below is an excerpt from Shiva-Naha Purana, where there is a dispute between Brahma- the Creator God and The Supreme Godhead Vishnu- The God who maintains the creation:
“Lord Vishnu saw a letter ‘A’ towards the south of that Shivalinga (The symbol by which shiva- the etrnal principle is worshipped; and which is exactly the same shape as the omphalos of the ancient mesopotamian and egyptian civilizations). He also saw the letters ‘U’ and ‘M’ centre towards the north of the Shivalinga and in its centre respectively. He also saw the mantra ‘OM’, which was dazzling like a Sun. There was no beginning and end to this mantra OM. As they were making efforts to know about its origin, suddenly Shiva appeared in the form of a sage. He gave them the knowledge regarding OM. He also revealed to them that Brahma originated from the letter ‘A’, Vishnu originated from letter ‘U’ and Shiva himself originated from letter M. The letter A signifies creation, U Signifies nurturement and M signifies salvation. The three letters A, V & M also symbolizes the basic causes of creation. A or Brahma also symbolizes the semen, U or Vishnu symbolizes the Vagina and the sound of OM is Maheshwar- the combined sound of A, U and M. All the three united from which manifested a golden egg. This golden egg remained submerged in the water for one thousand years. The almighty then cut that egg into two halves, from which appeared heaven and Earth.”