The hymn 3.19 of the Chāndogya Upaniṣad posits that the creation of the universe happened through a cosmic egg which materialized in the nothingness of the cosmic waters. Here’s Valerie Roebuck’s translation of the first two verses of this hymn:
1. The sun is the brahman: this is the symbolic statement. To explain further: in the beginning this was not-being. That was being; it came into existence; it turned into an egg. It lay for the space of a year, then cracked open. The two halves of the egg-shell became gold and silver.
2. What was the silver half is this earth, and what was the gold half is the sky. What was the chorion is the mountains, and what was the amnion is the mist with the clouds. What were the blood-vessels are the rivers, and what was the amniotic fluid is the sea.
In the hymn 6.2, the Chāndogya Upaniṣad deals with the problem of how “being” could emerge from “nothingness” or “non-being”. The arguments are being provided by Sage Uddalaka Aruni to his son, a young lad called Svetaketu. Uddalaka says:
1. ‘In the beginning, good lad, this was being, one alone without a second. Some say, “In the beginning this was non-being, one alone without a second. From that non-being, being was produced.”
2. ‘But, good lad, how could that be?’ he said. ‘How could being be produced from non-being? In the beginning, good lad, surely this was being, one alone without a second.
3. ‘It thought, “Let me become many; let me be born.” It created heat. Heat thought, “Let me become many; let me be born.” It created the waters. So when and wherever a person grieves or sweats, the waters are born from heat.
4. ‘The waters thought, “Let us become many; let us be born.” They created food. So when and whenever it rains food becomes more abundant. So good food is born from the waters.
The enigmatic conversation on various aspects of creation continues between Uddalaka and his son Svetaketu in the hymns that follow. The father and son are also present in the Bṛhadāraṇyaka Upaniṣad in which Uddalaka provides his philosophical insights on several issues.