We have often observed that most of the Hindu Mantras begin with an Aum and end with Swaha. What can be the primary reason behind it?
According to the philosophies of ancient Hindus sages, Aum comprises three sounds - 'a', 'oo', and 'ma'. Hindu beliefs also state that the word refers to the three supreme deities, the Holy Trinity, Lord Brahma, Lord Vishnu and Lord Mahesha.
According to the Dharma Shastras, the universe comprises three basic forms of energies, i.e., the Satva, the Rajas and the Tamas. While Satva relates to the godlike qualities, Rajas to the qualities of a human or king, the Tamas is related to demon-like qualities. Every element comprises energies with these three qualities in different proportions.
While the proportion of the energy can be changed, the composition remains the same. Combined together, these qualities become a completely pure mass. The word Aum is an assimilation of all the three energies or qualities also known as Gunas. Hence, the significance.
According to Hindu scriptures, an Aum not only symbolises Lord Shiva but Lord Ganesha as well. That is why Lord Ganesha is sometimes depicted in the form of an Aum as well. Since Lord Ganesha is worshipped at the beginning of every auspicious event, we chant Aum, signifying Lord Ganesha before beginning any sacred mantra.
It is said that when the universe was created, a sound of Aum was heard. The same sound would be heard when the universe will come to an end. Thus the primary sound holds great significance and we begin most of the mantras with this sound.
Balancing all the three forms of energies, relieving one of the mental stress this sound is believed to make one feel relaxed. When relaxed, one can concentrate better. Concentration is a vital element while chanting mantras if one wants to gain the benefits of the mantras. This is why, it is often also chanted at the beginning of both Raja Yoga and Hath Yoga exercises.