Holy Dialogue (Pravachana Vakhyalu):
April 08, 2014: The vidya has its origin, actually, in the Rig-Veda, in a famous sukta, or hymn, called the Purusha-Sukta. The Purusha-Sukta of the Rig-Veda commences by saying that all the heads, all the eyes, and all the feet that we see in this world are the heads, eyes, and feet of the Virat-Purusha, or the Cosmic Being. With one head, the Virat nods in silence; with another face He smiles; with a third one He frowns; in one form, He sits; in another form, He moves; in one form, He is near; in another form, He is distant. So, all the forms, whatever they be, and all the movements and actions, processes and relations, become parts of the Cosmic Body, with which the Consciousness should be identified simultaneously. When you think, you think all things at the same time, in all the ten directions, nay, in every way.
The Chhandogya Upanishad concludes this vidya by saying that one who meditates in this manner on the Universal Personality of Oneself as the Vaishvanara, becomes the Source of sustenance for all beings. Just as children sit round their mother, hungry, and asking for food, all beings in creation shall sit round this Person, craving for his blessings; and just as food consumed by this body sustains all the limbs of the body at once, this meditator, if he consumes food, shall immediately communicate his blessings to the whole Cosmos, for his Being is, verily, All-Being.
---Excerpts from Sri Chandogya Upanishad