Aum is a single, indivisible sound; it is the vibration of the Supreme. Aum is the seed-sound of the universe, for with this sound God set into motion the first vibration of His creation. The most powerful of all mantras is Aum; Aum is the mother of all mantras. At every second God is creating Himself anew inside Aum. Without birth is Aum, without death is Aum. Nothing else but Aum existed, exists and will forever exist.
Aum is a single Sanskrit character represented in English by three letters, but pronounced as one syllable. The syllable Aum is indivisible, but each portion of it represents a different aspect of the Supreme. The 'A' represents and embodies the consciousness of God the Creator, the 'U' embodies the consciousness of God the Preserver and the 'M' embodies the consciousness of God the Transformer. Taken together, Aum is the spontaneous cosmic rhythm with which God embraces the universe.
The sound of Aum is unique. Generally we hear a sound when two things are struck together. But Aum needs no such action. It is anahata, or unstruck; it is the soundless sound. A Yogi or spiritual Master can hear Aum self-generated in the inmost recesses of his heart.
There are many ways to chant Aum. When you chant it loudly, you feel the omnipotence of the Supreme. When you chant it softly, you feel the delight of the Supreme. When you chant it silently, you feel the peace of the Supreme.
The universal Aum put forth by the Supreme is an infinite ocean. The individual Aum chanted by man is a drop in that ocean, but it cannot be separated from the ocean, and it can claim the infinite ocean as its very own. When man chants Aum, he touches and calls forth the cosmic vibration of the supreme Sound. It is best to chant Aum out loud, so its sound can vibrate even in your physical ears and permeate your entire body. This will convince your outer mind and give you a greater sense of joy and achievement. When chanting out loud, the 'M' sound should last at least three times as long as the 'AU' sound.
No matter how grave a person's mistakes, if he chants Aum many times from the inmost depths of his heart, the omnipotent Compassion of the Supreme will forgive him. In the twinkling of an eye the power of Aum transforms darkness into light, ignorance into knowledge and death into Immortality.
Aum has infinite power; just by repeating Aum one can realise God. Everything that God has and everything that God is, within and without, Aum can offer, because Aum is at once the life, the body and the breath of God.
/You said we can increase our purity by repeating Aum five hundred times a day. But for me to repeat Aum five hundred times a day is very difficult. Can you advise me what to do?/
If it is difficult for you to do it at one stretch, then you can do it in segments. At ten different times you can repeat it only fifty times. Say that during the day you want to drink ten glasses of water. If you try to drink all ten glasses of water at once, you will not be able to do it. So you drink one glass now and after an interval of an hour or two another glass. Then easily you can drink ten glasses of water. Instead of chanting Aum five hundred times all at once, early in the morning you can repeat it Fifty times. Then, in an hour's time, do another fifty. Each hour if you repeat Aum fifty times, it won't take you more than a minute or two each time. Since you can easily offer two minutes in an hour to God, you can do your chanting in this way.