OM

Om or Aum (also Auṃ, written in Devanāgari(Hindi) as ॐ and as ओम्, in Sanskrit known as pranav प्रणव [lit. "to sound out loudly"], Omkara, or Auṃkāra (also as Aumkāra) ओंकार (lit. "Auṃ form/syllable"), is a sacred/mystical syllable in the Dharma or Indian religions, i.e. Sanatan Dharma, Hinduism, Jainism, and Buddhism.

Aum, pronounced as a long or over-long nasalized close-mid back rounded vowel, [õːː]) though there are other enunciations adhered to in received traditions. It is placed at the beginning of most Hindu texts as a sacred incantation to be intoned at the beginning and end of a reading of the Vedas or prior to any prayer or mantra. The Māndukya Upanishad is entirely devoted to the explanation of the syllable. The syllable consists of three phonemes, a Vaishvanara,[1] u Hiranyagarbha and m Iswara, which symbolize the beginning, duration, and dissolution of the universe and the associated gods Brahma, Vishnu, and Shiva, respectively.[2] Aum is pronounced in three sounds - A (aaa) , U (ooooo) and M (mmmmm) and signifies Right (A) and Left (U) Sympathetic Nervous Systems (SNS) and (M) Parasympathetic Nervous System.[citation needed) Right SNS (controlled by Left part of brain) looks after the actional aspect where as the left SNS looks after the emotional aspect of human beings.

The name Omkara is taken as a name of God in the Hindu.

The symbol AUM is composed of three syllables, namely the letters A, U, M, and when written has a crescent and dot on its top. A few instances of the various interpretations given to it may be mentioned here to convey its meaning.

The letter A symbolises the conscious or waking state ( jagratha-avastha ), the letter U the dream state ( svapna-avstha ) and the letter M the dreamless sleep state ( susupta-avastha ) of the mind and spirit. The entire symbol, together with the crescent and the dot, stands for the fourth state ( turiya-avastha ), which combines all these states and transcends them. This is the state of samadhi (1).

The letters A, U and M symbolise respectively speech ( vak ), the mind ( manas ) and the breath of life ( prana ), while the entire symbol stands for the living spirit, which is but a portion of the divine spirit.

The three letters also represent the dimensions of length, breadth and depth, while the entire symbol stands for the perfect man ( a sthita-prajna ), one whose wisdom is firmly established in the divine.

They represent the three genders, masculine, feminine and neuter, while the entire symbol stands for the Creator, who transcends the limitations of time.

They stand for the three gunas or qualities of sattva, rajas and tamas, while the whole symbol represents a gunatita, one who has transcended and gone beyond the pull of the gunas.

The letters correspond to the three tenses - past, present and future - while the entire symbol stands for the Creator, who transcends the limitations of time.

They also stand for the teaching imparted by the mother, the father and the Guru respectively. The entire symbol represents Brahma Vidya, the knowledge of the Self, the teaching which is imperishable.

The A, U and M depict the three stages of yogic discipline, namely, asana (2), pranayama (3) and pratyahara (4). The entire symbol represents samadhi (1), the goal for which the three stages are the steps.

They represent the triad of Divinity, namely, Brahma - the creator, Visnu - the Maintainer, and Siva - the Destroyer of the universe. The whole symbol is said to represent Brahman from which the universe emanates, has its growth and fruition and into which it merges in the end. It does not grow or change. Many change and pass, but Brahman is the One that ever remains unchanged.

The letters A, U and M also stand for the mantra 'Tat Twam Asi' ( 'That Thou Art' ), the realisation of man's divinity within himself. The entire symbol stands for this realisation, which liberates the human spirit from the confines of his body, mind, intellect and ego.

After realising the importance of AUM, the yogi focusses his attention on his beloved Deity adding AUM to the name of the Lord. The word AUM being too vast and too abstract, he unifies his senses, will, intellect, mind and reason by focussing on the name of the Lord and adding the word AUM with one pointed devotion and so experiences the feeling and meaning of the mantra.

The yogi recalls the verses of the Mundakopanisad : "Taking as a bow the great weapon of the Upanisad, one should put upon it an arrow sharpened by meditation. Stretching it with a thought directed to the essence of That, penetrate the Imperishable as the mark, my friend. The mystic syllable AUM is the bow. The arrow is the Self ( Atma ). Brahman is the target. By the undistracted man is It penetrated. One should come to be in It, as the arrow in the mark."


(1) Samadhi - a state of super-consciousness brought about by profound meditation, in which the individual aspirant ( sadhaka ) becomes one with the object of his meditation - Paramatma or the Universal Spirit.
(2) Asana - posture
(3) Pranayama - rhythmic control of the breath
(4) Pratyahara - withdrawal and emancipation of the mind from the domination of the senses and exterior objects

ॐ असतो मा सद्ग्मय ।

It is from the Shanthi Mantra(Prayer for peace) from The Bṛhadāraṇyaka Upanishad which is one of the older, primary Upanishad(Vedanta). The full Mantra and the meaning in English is given below -

ॐ असतो मा सद्ग्मय ।
तमसो मा ज्योतिर्गमय ।
मृत्योर्मा अमृतं गमय ।।
ॐ शांति: शांति: शांति: !!
- बृहदारण्यक उपनिषद् 1.3.27.

"Om asato ma sadgamaya,
Tamaso ma jyotirgamaya,
Mrityorma amritamgamaya
Om shantih shantih shantih"

Meaning:
Oh Almighty! Lead us from the unreal (falsity)
to the real (truth), from darkness to light!
From death to immortality!
Oh Almighty! May there be Peace! Peace! Peace!
-Brihdaranyaka upanisada 1:3:27 – India

3.Gayatri Mantra - गायत्री मंत्र

Gayatri (gaayatree) mantra is the most important and popular verse (shloka) of the Vedas (ved/s). Hindus love to chant this sacred religious shloka (shlok) as mantra (maNtra). It is  called 'Maha Mantra'.  means 'great mantra'!

Aum Bhur Bhuvah Swah, Tat Savitur Varenyam
Bhargo Devasya Dhimahi, Dhiyo Yo Nah Prachodayat

ॐ भूर्भुव: स्व: तत्सवितुर्वरेण्यं । भर्गो देवस्य धीमहि, धीयो यो न: प्रचोदयात् ।।

A basic translation can be given as...
Oh God, the Protector, the basis of all life, Who is self-existent, Who is free from all pains and Whose contact frees the soul from all troubles, Who pervades the Universe and sustains all, the Creator and Energizer of the whole Universe, the Giver of happiness, Who is worthy of acceptance, the most excellent, Who is Pure and the Purifier of all, let us embrace that very God, so that He may direct our mental faculties in the right direction.

4. MAHA MRITYUNJAYA MANTRA MEANING, SIGNIFICANCE.

Aum Trayambakam Yajamahe,
Sugandhim Pushtivardhanam;
Urva Rukamiva Bandhanaan,
Mrityor Mokshiye Maamritat.

ॐ त्रियम्बकं यजामहे, सुगन्धिं पुष्टिवर्धनं
उर्वारुकमिव बन्धनान् मृत्योर्मोक्षिय मामृतात्
OM triyambakam yajāmahe sugandhim pushTivardhanam,
urvārukamiva bandhanān mrrityormokshiya māmrritāt.
                               

Summary of the Maha Mrityunjaya Mantra

We worship Shiva - The Three-Eyed (tryambakam) Lord (yajamahe);
Who is fragrant (sugandhim) and nourishes (pushti) and grows (vardhanam) all beings.
As the ripened cucumber (urvarukamiva) is automatically liberated (bandhanaan) (by the intervention of the "farmer") from its bondage to the creeper when it fully ripens;
May He liberate us (mokshiya) from death (mrityor), for the sake of immortality (maamritaat).
We pray to Lord Shiva whose eyes are the Sun, Moon and Fire
May He protect us from all disease, poverty and fear
And bless us with prosperity, longevity and good health.

The Maha Mrityunjaya Mantra is a prayer to Lord Shiva (part of the hindu trinity, the lord of destruction, penance and meditation) for help in overcoming "death". The seeker is more concerned with avoiding spiritual "death" rather than physical "death". The mantra is a request to Lord Shiva to lead us to the mountain of meditation, which is indeed Lord Shiva's abode.

Legend has it that Lord Shiva appeared before his devotee Markandeya (who was destined to die at the age of sixteen) and stopped his aging process a few days before he was supposed to turn sixteen. Thus, death would never be able to claim him! Hence, this mantra is also referred to as the Markandeya mantra in classical hindu studies. The mantra should ideally be repeated 108 times, twice daily, at dawn and at dusk. It is particularly useful for meditation and yoga practice.