The Taittiriya Upanishad includes an insightful dialogue between Bhrigu, the inquisitive student, and his father, Varuna, the enlightened teacher. Bhrigu approaches his father Varuna with a sincere urge to know about Brahman and requests him to teach Brahmavidya.
… The teacher asks his disciple to concentrate all his energies towards understanding the subtlety of the various levels or sheaths “Food, the vital breath, the mind, the intellect… - That from which all are born, That by which, all sustain, and, That into which all finally merge- seek to know That. That is Brahman.”
… After a thorough analysis, he found that all hints which his father gave to him regarding Brahman are fulfilled by food (earth or matter). It is from food (earth) that we are born; food only keeps us alive, and finally our bodies disintegrate after death and go back into earth.
CONCLUSION 1: THE MATTER/FOOD IS BRAHMAN
… Brahman is eternal. He then tried to go deeper than the annamaya sheath (pertaining to food) and found that it is prana (the vital force) which supersedes body. Prana controls the body, Prana makes the body active. The moment prana leaves the body, the body gets disintegrated.
CONCLUSION 2: PRANA IS BRAHMAN
… After deep contemplation, he realized that prana or the vital breath was non-intelligent. There was something that controlled prana and decided when prana has to enter or leave the body. Therefore, he thought that prana could not be Brahman.
CONCLUSION 3: THE INTELLECT IS BRAHMAN
… He realized that it was the intellect which actually drove the mind in the necessary direction, and was, therefore, subtler than the mind. He saw that with the help of the intellect, one was able to determine what is right and what is wrong and could thus execute control over his mind.
CONCLUSION 4: … IS BRAHMAN
… At that point, Bhrigu identified that it could only be …
What is the final conclusion Bhrigu reached at, to know this and further more about the invaluable repositories hidden in the the Vedas and the Upanishads, read the complete article in October 2013 English Akhand Gyan monthly magazine.