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

The word "sva-śabda" (the word describing it) here means that the word
atomic is used to describe the individual spirit soul. An example of this is in
Muṇḍaka Upaniṣad (2.1.9):
eṣo 'ṇur ātmā
"The soul is atomic in size."
The word "unmāna" here means "Its measurement is atomic in size". The
precise measurement of the individual spirit soul is given in the Śvetāśvatara
Upaniṣad (4.9):
bālāgra-śata-bhāgasya
śatadhā kalpitasya ca
bhāgo jīvaḥ sa vijñeyaḥ
sa cāntantyāya kalpate
"When the upper point of a hair is divided into one hundred parts and again
each of these parts is further divided into one hundred parts, each such part is the
measurement of the dimension of the spirit soul."*
In these two ways the atomic size of the soul is proved. the word ānantya" here
means "liberation". "Anta" means "death", and "an" means "without". Therefore
the word "ānantya" means "the condition of being free from death".
Here someone may object: Is it not so that if it is atomic in size and situated in
a specific place in the material body, the soul could not perceive sensations in all
other parts of the body, where the soul is not actually present?
If this is said, then the author of the sūtras replies in the following words.
Sūtra 22
avirodhaś candana-vat
avirodhaḥ—not contradicting; candana—sandal; vat—like
It does not contradict. It is like sandal paste.
Purport by Śrīla Baladeva Vidyābhūṣaṇa