Sri Sathya Sai Speaks

Although there are many letters and words, the fundamental aksharam (letter), which has primacy of place, is the Omkara. 'Om ithyekaksharam Brahma (the single letter OM is Brahman Itself)', says the Geetha. All other letters and words are linguistic creations. They do not possess the unique sacredness and divine character of 'OM.' The special significance of 'OM' is not generally recognised or understood. The Manthra Shasthra (ancient scripture related to sacred formulas) has laid emphasis on the letter 'OM'. Omkara has no form. It is the manifestation of Brahman as sound. It is present in all creation. It is effulgent. It is in all speech. It is ever blissful. It is Parathparamyee (embodiment of the Supreme). It is Mayamayee (the repository of illusory power). It is Shreemayee (embodiment of prosperity). The Omkara is the only sound that has these eight divine attributes, according to the Manthra Shasthra.
 
- Divine Discourse, 01 October 1984, Sri Sathya Sai Speaks, Vol 17 (1984)
 
Bhagawan advices starting the day with Omkaram chanting – OM (x 21). He further enunciates: The Pranava (primeval sound OM) recital is one form of such spiritual effort. It is laid down at Prashaanthi Nilayam that the early dawn recital of Om should be done twenty one times. This number is not arbitrarily fixed; it has a significance of its own.

1. We have the five karmendhriyas (senses of action) and the five jnaanendhriyas (senses of perception);
2. we have also praanas (the five vital energies or airs) to sustain us.
3. Then we have the five koshas (sheaths), enclosing the Divine Spark that is the Reality. These total up to twenty.
4. Hence the recitation of Om twenty one times purifies and clarifies all these twenty components and makes man the twenty-first entity, ready for the final merger with Reality.

The Jeevathathwam (life-principle) merges with Parathathwam (the Supreme Reality). The jeevathathwam may be pictured as a rider on the twenty-headed horse. Finally, you end the Pranava recital with the recital of ‘shaanthi’ three times. That completes the process of clarification and purification. The first call for shaanthi (peace chant) is for the purity of the aadhibhouthik (body) part of the Self. The second call is for the purity of the aadhidhaivik (the mind). The third is for the purification of the aadhyaathmik (the spirit). This Pranava recital will tone you up, calm all agitations in the mind and quicken the downpour of Grace.
 
- Bhagawan Sri Sathya Sai Baba, Bal Vikas Gurus Training Camp, 06th June 1978, Sathya Sai Speaks, Vol 14 (1978 - 80)