गोविन्द भाष्य (श्रील बलदेव विद्याभूषण - अचिन्त्यभेदाभेद वेदान्त ब्रह्मसूत्र भाष्य सटीक)

This also refers to air.
Purport by Śrīla Baladeva Vidyābhūṣaṇa
This proof that ether was created clearly shows that air, which exists within
ether, must also have been created. That is the meaning. This is so because the
limbs of something must have the same qualities as the whole of which they are
parts.
Our opponent may object: Because it was never described in the Chāndogya
Upaniṣad, it is clear that air was never created.
To this I reply: The Taittirīya Upaniṣad explains that air was created from ether.
Then our opponent may say: That description of the creation of air must have
been a figure of speech, because the Śruti-śāstra explains that air is eternal.
To this I reply: The Chāndogya Upaniṣad affirms in a pratijñā statement (aitad-
ātmyam idaṁ sarvam) that everything was created by the Supreme Personality of
Godhead. In this way the creation of air is proved. When it is said that air is
eternal the intention is that it is so only relative to some other things. Air was
discussed in a separate sūtra and not discussed together with ether. This was done
to facilitate the argument of Sūtra 9.
Adhikaraṇa 3
The Eternal Supreme Personality of Godhead Is Not Created
Introduction by Śrīla Baladeva Vidyābhūṣaṇa
The Chāndogya Upaniṣad (6.2.1) affirms:
sad eva saumyedam
"O gentle one, in the beginning the Supreme Personality of Godhead alone
existed."
A doubt may arise about this statement. Was the eternal Supreme Personality of
Godhead created or not? Pradhāna, mahat-tattva, and many other things that are
causes or creators of other things were created, so perhaps the Supreme