" Know that which pervades the entire body is indestructible. No one is able to destroy the imperishable soul."
This soul is described as one ten-thousandth part of the upper portion of the hair point in size.
The Śvetāśvatara Upaniṣad confirms this:
bālāgra-śata-bhāgasya śatadhā kalpitasya ca
bhāgo jīvaḥ sa vijñeyaḥ sa cānantyāya kalpate.
"When the upper point of a hair is divided into one hundred parts and again each of such parts is further divided into one hundred parts, each such part is the measurement of the dimension of the spirit soul." (Svet. 5.9) Similarly, in In
In Srimad Bhāgavatam the same version is stated:
keśāgra-śata-bhāgasya śatāṁśaḥ sādṛśātmakaḥ
jīvaḥ sūkṣma-svarupo 'yaṁ saṅkhyātīto hi cit-kaṇaḥ
"There are innumerable particles of spiritual atoms, which are measured as one ten-thousandth of the upper portion of the hair."
In the Muṇḍaka Upaniṣad the measurement of the atomic spirit soul is further explained:
eṣo 'ṇurātmā cetasā veditavyo
yasmin prāṇaḥ pañcadhā saṁviveśa
prāṇaiś cittaṁ sarvam otam prajānāṁ
yasmin viśuddhe vibhavaty eṣa ātmā.
"The soul is atomic in size and can be perceived by perfect intelligence. This atomic soul is floating in the five kinds of air [prāṇa, apāna, vyāna, samāna and udāna], is situated within the heart, and spreads its influence all over the body of the embodied living entities. When the soul is purified from the contamination of the five kinds of material air, its spiritual influence is exhibited." (Muṇḍ. 3.1.9)
The atomic soul has a mind and body made in the image of its parents. It has taken a personality, specific physical features from the genes it inherited from its biological creators down to its ancestors. So, we can not blame ourselves if we suffer hypertension, diabetes, asthma etc since these diseases are inherited. It`s bad karma if they say we are dumb, stupid, ugly, crazy or deformed. Good karma if we are pretty or handsome, bright , talented, rich and hardworking. We actually inherited them from the genes of our parents and forefathers. These are all external. What is internal or eternal is the atomic soul found in everyone of us. If we grow old, its because the atomic soul is decaying ( Alpha ). If the atomic soul stabilizes into an Om particle, the body becomes immortal (Omega) e.g Jesus Christ