Chandogya Upanishad ...about
It is the longest of the Upanishads, and consists of 8 chapters attached to the first part of the Chandogya Brahmana in the Sama Veda, describing ritual sacrifices.
It contains (6.8.7) the maha vakya considered the essence of Sama Veda:
tat tvam asi, "you are That (Brahman)".
• It also narrates the famous story of Satyakama Jabala, a boy son of a maidservant, who was recognized as brahmana due to the sense of truthfulness he had demonstrated.
Other Upanishads contain the teachings of Satyakama Jabala, but here (4.4.1) we find the story of how he entered the gurukula of Haridrumata Gautama.
Within the text we also find many explanations on Vedic symbolism, especially in regard to the fire sacrifice and the mantras in relation to the life energy in the human body and in the senses, and in relation to the Sun
. • "If someone offers the sacrifice to the fire without knowing these (things), it is as if he was removing the blazing embers and pouring the clarified butter into the ashes... If someone knows these (things) even the act of offering one's food leftovers to a chandala becomes an offering to Vaisvanara Atman (the sacred fire of the Self)." (5.24.1, 4) 11
• "One must meditate on the syllable Om, that gives origin to the Udgita (the songs of the Sama Veda). The essence of all bodies is the earth, the essence of earth is water, the essence of water is vegetation, the essence of vegetation is the human being, the essence of the human being is speech, the essence of word is mantra (rik), the essence of rik is Sama." (1.1.1)
• The text then illustrates meditation on sound and prana and their identity with the Sun, that is svara and pratyasvara ("coming and going", i.e. cyclic) and states that the realization of the Pranava Omkara, its subtle manifestation, awards immortality.
• Then it explains the symbolic meaning of syllables in vedic definitions, the power of prana and sound, and the subtle element known as akasha ("etheric space") that supports both.
• The 4th chapter repeats the explanation of creation starting from Brahman (Being), that from One wanted to become many. Thus he created fire, then from fire water was created and from water the nutritious substances, and then these 3 divine essences manifested all the bodies of the beings, when Brahman entered into them, in the form of Jiva Atman.
• What is red is fire (passion),
what is white is water (goodness or purification) and
what is black is food (earth, ignorance), both in fire and in the sun and in the qualities of material nature in general.
• The text also offers the conversation between Svetaketu and his father Uddalaka Aruni, rich with teachings and practical examples to understand the nature of Brahman;Atman.
We also find the mystic etymology of the word satyam, "truthfulness" or "truth": sa indicates what is eternal, ti indicates what is temporary, and ayam is the connection between the two. • Then the 8th chapter teaches than only brahmacharya ("behaving as Brahman") enables one to realize Brahman, and that the difference between Devas and Asuras is that Asuras identify with the material body and consider it the true self.