The Mahavakyas are the great sentences of Advaita Vedanta and Jnana Yoga and are mentioned in the Upanishads. Maha is Great and Vakyas are sentences, or utterances for meditation. They provide perception and insights that combine the texts together in a consistent whole. The contemplations on the Mahavakyas also merge well with the practices of yoga meditation, prayer, and mantra, which are associated practices in Yoga. The apex of the wisdom and practices of the ancient sages is mentioned in the twelve brief verses of the Mandukya Upanishad, which outlines the philosophy and practices of the AUM mantra. The Mahavakyas emerged to condense the meaning of the majestic Vedas. Mahavakyas are the "Great Sayings" of the Upanishads and the foundational texts of Vedanta. Each of the Mahavakyas is related with one of the four Vedas and in Vedantic mysticism. The Mahavakyas provides the essence of entire Veda in one statement..

All four Mahavakyas indicate the ultimate unity of the individual (Atman) with God (Brahman).

The Mahavakyas of the Upanishads are as follows -

Ayam Atma Brahma - "This Self (Atman) is Brahman" (Mandukya Upanishad 1.2 of the Atharva Veda)

Prajnanam Brahma - "Consciousness is Brahman" (Aitareya Upanishad 3.3 of the Rig Veda)

Aham Brahmasmi - "I am Brahman" (Brhadaranyaka Upanishad 1.4.10 of the Yajur Veda)

Tat Tvam Asi - "Thou art That" (Chandogya Upanishad 6.8.7 of the Sama Veda)

The Mahavakyas make the wisdom more accessible. Seven Mahavakyas are followed generally and by focusing on these the rest of the principles of self-exploration described in Vedanta and the Upanishads are more easily understood.

To understand the meaning of the Mahavakyas, it is necessary to practice meditation and the inner area is of stillness and silence. Sadhana means practicing a lot of self-observation, including the four functions of mind. Mahavakyas are not practiced as blind faith beliefs, but rather are reflected on by many experts so that their meaning is validated in direct experience.

Some methods of sadhana give the sadhak a principle, a word, on which he usually reflects, but if he concentrates on Mahavakyas, the effectiveness is much faster. In other cases or mantrams, it might take a long time to come to a core principle. In contemplating the Mahavakyas, it is not a matter of merely accepting that the statements are true. In the oral teachings of the sages found in scriptures, it is said that no one should merely believe what is told or written in religious books. Rather, it is suggested that one should check it either in the scriptures or experience personally. Ultimate oneness is the same for all; there is also a colouring of cultural and religious influences that determine the way in which different people will experience the early or describing stages of insight.

The passionately dedicated practitioner will contemplate on one or more of the Mahavakyas repeatedly over a long period of time. Mind gradually comes to have a superior understanding, and then the mind becomes still as the meditation shifts from an observing, reflective process into a deep contemplative meditation. Reflection transforms into insight, which again transforms into the direct practice of the essential truth or reality of the Mahavakya.

In the oral tradition of the Himalayan sages, the Yoga Sutras, Vedanta, and internal Tantra are related events on the journey to Self-Realization. The practices of the Yoga Sutras soothe and clear the clouded mind. The Vedanta practices form a philosophical basis and typical means for discovering the primary unity of the different aspects of human being. Internal Tantra provides the means for awakening the spiritual energy, so that the absolute, unchanging reality at the ultimate depth is realized.

Mahavakyas are at the heart of Vedanta and these principles emerged out of the one source of teachings, and now appear to be three separate practices. The higher understanding and direct experience derives from person-to-person listening (written and oral), followed by deep manifestation, meditation, and deep thoughtful meditation. Advaita means non-duality and stands alone. To transcend all of the levels of false identity so as to "Be" that Reality of Advaita is the Knowledge or Jnana that is searched. It is only the most sincere and longing of aspirants who seek and know this in direct experience. For others, it is merely an arena of philosophical and spiritual debate.

Mahavakyas are still some of the core statements used by hermits and sages to train their disciples throughout India. The Mahavakyas have become more of proverbs in Indian Literature than texts of scriptures.