Hari Om. The entire universe is the syllable Om.
Everything in the past, present, and future is verily Om.
That which is beyond time, space, and causation is also Om.
—Mandukya Upanishad (mantra 1)
The Vedas are the oldest-known scriptures, containing mantras that were revealed to the great sages in deep meditation. There are four Vedas: Rig, Sama, Yajur, and Atharva. The Upanishads are the philosophical culmination of the teachings of the Vedas, and are known as Vedanta. The Mandukya Upanishad, which is the shortest Upanishad with only 12 mantras, is part of the Atharva Veda, and is considered to be the most profound of all the Upanishads. Mantra 26 of the Muktika Upanishad says: “[Knowledge of] the Mandukya Upanishad alone is sufficient for the determined seeker to attain liberation.” The commentary Mandukya Karika of Gaudapada, Shankara’s teacher’s teacher, is one of the deepest expositions on Advaita Vedanta.
The Mandukya Upanishad is considered to be the most profound of all the Upanishads.
The mystic symbol Om, or AUM, represents pure consciousness, the original source of all that which is manifested in the world—all forms, speech, thoughts, desires—as well as all that which remains unmanifested. This primordial sound is the name of Absolute Reality, which is not subject to change. Whatever has happened in the past, or is happening in the present, or will happen in the future has no effect on it, for it is beyond the confines of time, space, and causation.
The primordial sound Om is the name of Absolute Reality, which is not subject to change.
According to the Himalayan sage Swami Rama, the entire teachings of the Upanishads are condensed in the knowledge of Om. If one can penetrate and understand the sound of AUM on all its levels—waking (A), dreaming (U), deep sleep (M), and turiya, or the state beyond (the silence after AUM), as well as the gross, subtle, causal, and beyond—one will come to know the true essence of life, the universe, and Absolute Reality.
Worldly pleasures are transient, but the truth of Om is eternal—it expands our individual consciousness to universal consciousness. The Upanishads say the more we meditate and contemplate on Om, the more our spiritual awareness will deepen. But experienced teachers caution us not to use Om alone as a meditative mantra to focus the mind; it is not practical as it will withdraw our minds from worldly thoughts and we will not be able to fulfill our worldly obligations. Rather, Om is recommended for deep contemplation and meditation for renunciates and advanced students—those who have studied the Upanishads in depth and who are ready to turn their minds fully inward.
Worldly pleasures are transient, but the truth of Om is eternal—it expands our individual consciousness to universal consciousness.
We can start to prepare our minds to receive the wisdom of Om with daily meditation, and with the use of it as the first sound of a longer mantra, such as the gayatri or the maha mrityunjaya mantra, or as an invocation at the beginning of a prayer, a scripture, or a class. Its powerful vibration will begin to resonate on a deeper level of our minds and hearts, reminding us of that which is ever within us—our eternal unchanging source, from where we have come, and to where we will return.