in bg 15.18 srila prabhupada wrote in the purport section -
(Chāndogya Upaniṣad 8.12.3): tāvad eṣa samprasādo ’smāc charīrāt samutthāya paraṁ jyoti-rūpaṁ sampadya svena rūpeṇābhiniṣpadyate sa uttamaḥ puruṣaḥ. “The Supersoul coming out of the body enters the impersonal brahma-jyotir; then in His form He remains in His spiritual identity.
please someone can elaborate this in simple words ? supersoul coming out of the body means 'our body' ?
Replies
Hare Krsna
Srila Prabhupada has explained and emphasized in the purport itself.
The Supersoul coming out of the body enters the impersonal brahmajyoti - body refers to material body of living entity
then in His form He remains in His spiritual identity. - means despite entering the impersonal brahmajyoti, the spiritual identity of the Supersoul is retained.
That Supreme is called the Supreme Personality - Here SP emphasizes that the supersoul itself is the Supreme personality of godhead or Bhagavan
This means that the Supreme Personality is exhibiting and diffusing His spiritual effulgence, which is the ultimate illumination. Here SP is emphasizing that the ultimate effulgence of brahmajyoti is one of the exhibition of the Supreme Personality or Bhagavan
That Supreme Personality also has a localized aspect as Paramätmä. - Here SP again says that Bhagavan's another manifestation is Paramatma which is localized as Supersoul.
By incarnating Himself as the son of Satyavati and Parashara, He explains the Vedic knowledge as Vyasadeva.- Here Sp says about the functional incarnation of lord as Vyasadeva for the purpose of giving knowledge.
In summary SP is saying that - There are many manifestations of Supreme lord -
1. Bhagavan or Supreme personality of Godhead which is the ultimate
2. Paramatma or localized aspect of lord which always retains identity
3. Brahmajyoti or Ultimate spiritual effulgence
4. Incarnation - Example Vyasadev for providing vedic knowledge.
Hare Krsna
For better understanding that sloka, maybe its better you read all chapter :
Chandogya Upanishad ,part 8, chapter 12.
1. "O Indra, this body is mortal, always held by death. It is the abode of the Self which is immortal and incorporeal. The embodied self is the victim of pleasure and pain. So long as one is identified with the body, there is no cessation of pleasure and pain. But neither pleasure nor pain touches one who is not identified with the body.
2—3. "The wind is without body; the cloud, lightning and thunder are without body. Now, as these, arising from yonder akasa and reaching the highest light, appear in their own forms, "So does this serene Being, arising from this body and reaching the transcendental Light, appear in His own form. In that state He is the Highest Person. There He moves about, laughing, playing, rejoicing—be it with women, chariots, or relatives, never thinking of the body into which he was born. "As an animal is attached to a cart, so is the prana (i.e. the conscious self) attached to the body.
4. "When the person in the eye resides in the body, he resides where the organ of sight has entered into the akasa (i.e. the pupil of the eye); the eye is the instrument of seeing. He who is aware of the thought: ‘Let me smell this,’ he is the Self; the nose is the instrument of smelling. He who is aware of the thought: ‘Let me speak,’ he is the Self; the tongue is the instrument of speaking. He who is aware of the thought: ‘Let me hear,’ he is the Self; the ear is the instrument of hearing.
5. "He who is aware of the thought: ‘Let me think this,’ he is the Self; the mind is his divine eye. He, the Self sees all these desires in the World of Brahman through the divine eye, the mind and rejoices.
6. "The gods meditate on that Self. Therefore all worlds belong to them and all desires. He who knows that Self and understands It obtains all worlds and all desires." Thus said Prajapati, yea, thus said Prajapati.
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Bg 15.18 — Because I am transcendental, beyond both the fallible and the infallible, and because I am the greatest, I am celebrated both in the world and in the Vedas as that Supreme Person.
Srila Prabhupada said in the purport of Bg.15.18 :
The Supreme Lord, in His localized aspect of Paramātmā, is also described in the Vedas themselves. The following verse appears in the Vedas (Chāndogya Upaniṣad 8.12.3): tāvad eṣa samprasādo ’smāc charīrāt samutthāya paraṁ jyoti-rūpaṁ sampadya svena rūpeṇābhiniṣpadyate sa uttamaḥ puruṣaḥ. “The Supersoul coming out of the body enters the impersonal brahma-jyotir; then in His form He remains in His spiritual identity. That Supreme is called the Supreme Personality.” This means that the Supreme Personality is exhibiting and diffusing His spiritual effulgence, which is the ultimate illumination.
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God is mentioned in Chandogya Upanishad 8.12.3. as uttama purusha (Highest Person or Supreme Person)