Vyahriti or Mahavyahriti in Hinduism is the seven worlds represented by mystic syllables. It denotes the seven worlds – bhuh, bhuvah, svah, mahah, janah, tapah and satya, one above the other, commencing with the earth.
According to Taittiriya Upanishad, the first three syllables enable us to know the mahah (fourth one), the Supreme Brahman, the being. The fourth one is stated to be the sun, since all the worlds gain strength from this or the moon since all the luminous bodies gains splendor from this; or food since all vital breaths derive their strength from this. The first three are identified, respectively with the three Vedas, Rig, Sama and Yajur. The first three are most important and are prefixed to the Gayatri mantra, along with the syllable om. They are held as the three faces of Brahma.
These three syllables are employed at the time of the installation and worship of deities and while doing vyahrtihoma (an oblation). On account of the importance of these three syllables, they are repeated first and then all the seven. Bhuh denotes the world in which we take birth on account of our past deeds, enjoy the fruits of our past actions and perform the actions leading to our next birth.
Bhuvah denotes the intermediate region between heaven and earth, extending up to the region of the moon and known as the world of the pitrs (Pitriloka), attained by one after his death on account of his meritorious deeds like making gifts, etc. Such a person is reborn on the earth on account of this attachment for the earth. The path of such people is known as the pitryana.
Even while remaining in the bhuvarloka, if one sheds his attachment to the earth and becomes sanctified, he will proceed to the svahaloka, situated beyond the solar region and known differently as swarga and Indraloka. Such of those who have shed their attachment for the life on earth attain this world by the path of devayana. Men proceed further to the other subtle higher worlds Maharloka, Janolaka, Tapoloka and Satyaloka. Only very few attain liberation (sadyomukti) in these worlds on account of their knowledge.
Those who are incapable of taking to anyone of these two paths (pitrayana and devayana) attain lower births in which they suffer and repent and later take to one of these paths at the appropriate time. When the three worlds are submerged at the time of the deluge, the inhabitants of the Maharloka move upward to the Janoloka. While repeating the Vedic hymns, one is required to know the rishi, the meter, and the deity relating to the particular hymn. Otherwise, the repetition of the hymns will not confer the desired fruits. Similarly, one has to know the sage, meter and deity associated with the vyahritis.
The sages of these vyahritis are Atri, Bhrigu, Kutsa, Vasistha, Gautama, Kashyapa and Angirasa, respectively, according to one tradition and Vishwamitra, Jamadagni, Bharadvaja, Gautama, Atri, Vasistha and Kashyapa, according to another tradition. Gayatri, Usnik, Anustubh, Brhati, Pankti, Tristubh and Jagati are the respective meters. Fire-god, wind-god, sun-god, Brihaspati, Varuna, Indra and Vishvedevah (all gods) are the respective deities. Prajapati is said to be the deity of the seven syllables collectively.
Before commencing the oblation one has to contemplate on these deities as having a pleasant countenance, adorned with flowers and sandal paste etc. The colors of these syllables are white, coppery red, variegated, yellow, red and golden. One may be seated in the swastika or virasana posture while repeating the mantra or offering the oblation. The syllables are assigned on the hand (karanyasa), on the body (dehanyasa) and on parts of the body (anganyasa). In the first one, the first five syllables are assigned on both the hands beginning with the thumb and ending with the little finger and the remaining two on the palms. In the second one, it is done on the foot, knee, thigh, below the navel, chest, hand, and face and concluding with the syllable on the head. Alternatively, the syllables are assigned on the head, the two arms, feet, left hand, left shoulder, right hand and right shoulder. In the third one, the syllables are assigned on the heart, head, tuft, outside the eyes, the two sides and in the ten directions. The syllable om, the first three vyahrtis and the Gayatri mantra are declared as capable of washing away all inauspicious acts and conferring immense benefits. Whoever knows the seven syllables knows the Brahman.