More about the qualities of the soul (Bg 2.22 to 2.25)
The soul can never be cut to pieces by any weapon, nor burned by fire, nor moistened by water, nor withered by the wind. The soul is unbreakable and insoluble, and can be neither burned nor dried.
« The Song of God: An in-depth study of the Bhagavad-gītā (Volume 1)
Verse 22: vāsāmsi jīrṇāni yathā vihāya, navāni gṛhṇāti naro ’parāṇi
tathā śarīrāṇi vihāya jīrṇāny, anyāni samyāti navāni dehī
As a person puts on new garments, giving up old ones, the soul similarly accepts new material bodies, giving up the old and useless ones.
Verse 23: nainam chindanti śastrāṇi, nainam dahati pāvakaḥ
na cainam kledayanty āpo, na śoṣayati mārutaḥ
The soul can never be cut to pieces by any weapon, nor burned by fire, nor moistened by water, nor withered by the wind.
Verse 24: acchedyo ’yam adāhyo ’yam, akledyo ’śoṣya eva ca
nityaḥ sarva-gataḥ sthāṇur, acalo ’yam sanātanaḥ
This individual soul is unbreakable and insoluble, and can be neither burned nor dried. He is everlasting, present everywhere, unchangeable, immovable and eternally the same.
Verse 25: avyakto ’yam acintyo ’yam, avikāryo ’yam ucyate
tasmād evam viditvainam, nānuśocitum arhasi
It is said that the soul is invisible, inconceivable and immutable. Knowing this, you should not grieve for the body.
In his commentary, Srila Baladeva Vidyābhūṣaṇa mentions that after verse 2.21, Arjuna could have thought that even though the soul does not die, still the bodies of men such as Bhīṣma and others would be destroyed in the battle. This would be improper since it would deprive the respective souls of the material happiness they would otherwise enjoy in these bodies.
This possible argument is, however counteracted by Krsna in verse 2.22. The change of bodies is just like changing clothes. Just like we don't lament when a person changes old clothes for new ones, we should not lament for the soul changing from an old body into a new one. Prabhupada already commented on this point in verse 2.13:
"There was no cause for lamentation by Arjuna on account of death, neither for Bhīṣma nor for Droṇa, for whom he was so much concerned. Rather, he should rejoice for their changing bodies from old to new ones, thereby rejuvenating their energy. Such changes of body account for varieties of enjoyment or suffering, according to one’s work in life. So Bhīṣma and Droṇa, being noble souls, were surely going to have spiritual bodies in the next life, or at least life in heavenly bodies for superior enjoyment of material existence. So, in either case, there was no cause of lamentation."
Once, Nārada Muni met a brahmacārī who led a pure life, completely faithful to the service to the spiritual master. Nārada blessed him to "die immediately", since being so pure, he would immediately go back to Godhead. Next, he met a prince, whom he blessed to "live a long life", since the prince was now immersed in sense gratification, and therefore his situation after death would be precarious. Living for a long time, he could at least enjoy for some time, and maybe become renounced and start the spiritual path later in life. Finally, he met a butcher, whom he blessed to "not live and not die". The butcher was already living a hellish life because of his occupation, and after death, he would be immediately carried by the Yamadūtas to hell. The cryptic blessing highlighted how implicated he was.
Since the soul is eternal and the body is temporary, everyone will have to leave their bodies one day. For one who takes birth, death is certain. The point is thus about living a progressive life and dying in favorable circumstances, and not about prolonging our lives at all costs. For a kṣatriya, dying while fighting on the battlefield is beneficial because it destroys his sins and promotes him to the celestial planets. In the specific case of the battle of Kurukṣetra, the benefit would be even greater, since all the soldiers and generals who would fall in battle would attain liberation due to the personal presence of the Lord.
The Lord then proceeds to describe more characteristics of the soul. Nainam chindanti śastrāṇi: the soul can't be cut into pieces by any type of weapon. All modern weapons are classified as fire weapons according to the Vedic definition since they are based on the use of explosions, flames, radiation, or electricity, which are all manifestations of the fire element. In previous times, kṣatriyas had also mystic weapons based on the elements earth, water, and wind, but none of these weapons, modern or ancient can affect the soul, which is acchedyaḥ (unbreakable), adāhyaḥ (impossible to burn), akledyaḥ (insoluble) and aśoṣyaḥ (impossible to dry).
The soul is also sarva-gataḥ (all-pervading) because it can enter anywhere in the creation. Since the soul can enter everywhere, it means there is life everywhere in the creation, including places like the sun, with the soul assuming bodies appropriate for the conditions there. The Sun is described as a celestial planet, an extremely opulent place presided over by Surya. This abode, however, is so luminous that we can't even look at it, so how can one believe that it is possible to live there? Certainly not in our current bodies, but extraordinarily pious souls receive bodies appropriate to live there.
The soul is also described as acalaḥ (immovable) because it can't be moved in or out of the body by mechanical means, nor can the transmigration to a new body after death be stopped. In a higher sense, however, acalaḥ means the soul resides eternally in his eternal position, being the material identity a mere reflection of the consciousness of the soul, which is then covered by the false ego, mind, intelligence, senses, and gross body, as explained in detail in the teachings of Lord Kapila in the third canto of Srimad Bhagavatam. This material identity, encased in the subtle body, transmigrates from one body to the other, while the soul proper resides eternally in the spiritual sky, just as the light of the moon is reflected in a pot of water. However, because this explanation is so complicated, it is often said that the soul transmigrates from one body to the other, which explains the main principle (we are not the body) without entering into all the difficult details. In Sanskrit, the word for "soul" is ātmā, which is a term difficult to translate because it can mean different things in different contexts. Ātmā, which means "the self," can be used in the sense of the individual soul, the Supersoul, the material consciousness, the mind or intellect, or even the body itself. The word "soul" is used as a loose translation for this complex term.
The soul is also defined as avyaktaḥ (invisible) because it can't be found by experimental means. In fact, the soul can't be studied by any kind of scientific or experimental process. The only reliable source of knowledge about the soul is the Vedas. Just as one can't understand the identity of his father except by asking the mother, one can't understand the soul except by studying the scriptures.
The soul is also described as sthāṇuḥ (unchangeable) and sanātanaḥ (eternally the same), as well as avikāryaḥ (immutable). As Prabhupada explains, these characteristics described by Krsna directly contradict the Māyāvāda interpretation that the souls are separated parts of the Supreme Brahman and merge back into it after liberation. As Krsna explains, the soul is not a lump of matter that can be broken and recombined. The soul is an immortal particle that is always the same, immutable, and unchangeable. This reinforces the conclusion that the soul is eternally a separated individual. As defined by Sri Caitanya Mahāprabhu, we are simultaneously one with Krsna (sharing the same spiritual characteristics), and different, because we are eternally separated individuals. Just as we are separated individuals here, we will continue being separated in the spiritual world, the only change will be in the quality of our consciousness and activities. There is no possibility of merging into anything or anyone anywhere in the creation. Even if one attains impersonal liberation in the brahmajyoti, still there is no merging; the individual soul is simply put in the effulgence of Krsna, from where it can fall back into the material world in search of variety.
Main points in the purports of Srila Prabhupada:
"As a person puts on new garments, giving up old ones, the soul similarly accepts new material bodies, giving up the old and useless ones."
a) The fact the body continuously changes but the person still remains the same is a logical proof of the existence of the soul. Apart from all changes in the body, the soul remains as it is, and at the time of death, the soul is transferred to another body.
b) Who is responsible for the transfer of the soul from one body to another? The Supersoul does it according to one's desires and activities, just as a friend fulfills the desire of another. The soul and the Supersoul are like two birds sitting on the tree of the body, one enjoying the fruits of the tree, and the other simply observing. They are friends, but at the same time, one is the master and the other the servant. Because of forgetfulness, the soul continues to go from one tree to another, and in each body, one struggles very hard. When we turn to the Lord and accept His instructions, however, we become free from all lamentation.
c) Brāhmaṇas sometimes kill animals in religious sacrifices, and similarly, kṣatriyas kill enemies in battle. Both the animals sacrificed and the warriors killed are purified of past reactions and promoted to a higher status of life. That's another reason for Arjuna not lamenting the death of Bhīṣma and Droṇa.
"The soul can never be cut to pieces by any weapon, nor burned by fire, nor moistened by water, nor withered by the wind."
a) In previous eras, kṣatriyas possessed mystical weapons based on the manipulation of all four elements, including not only fire but also water, air, and earth. These weapons were not chemical or mechanical, but controlled by mantras capable of manipulating the material elements. By using the appropriate mantras, a kṣatriya could produce a tornado to attack his enemies, for example. Arjuna possessed many such mystical weapons, but none of the weapons at his disposal were able to kill the soul.
b) The Māyāvādi theory that the Supreme Brahman became fragmented into many souls by being covered by ignorance is false. The Supreme Brahman can't be covered by Maya, nor cut into pieces.
c) The correct understanding is that the souls are eternally separated from the Lord, and being individuals they have free will and have thus the possibility of being covered by the material energy and becoming thus separated from the association of the Lord, just as sparks may fall out of a fire, although being one in quality with the fire.
d) The living entity is a separate individual at every stage. After being liberated from illusion, the living entity maintains his separate identity, as described in the Bhagavad-gītā. The soul becomes liberated from material contamination, but never becomes one with Krsna.
"This individual soul is unbreakable and insoluble, and can be neither burned nor dried. He is everlasting, present everywhere, unchangeable, immovable and eternally the same."
a) The theory of monism, that the soul merges into the Supreme Brahman is very difficult to maintain when faced with the verses of the Bhagavad-gītā because so many verses reinforce that the soul is an eternal separate particle and remains eternally the same without change.
b) What the impersonalists call merging into the Supreme is simply the soul being put into the Brahmajyoti, the effulgence of Krsna. The intelligent, however, prefer to enter into the spiritual planets to associate with the Lord.
c) The word sarva-gata (all-pervading, living everywhere) indicates that the soul can live in any part of the creation. Everywhere, there are living beings with bodies adapted to the environmental conditions.
"It is said that the soul is invisible, inconceivable and immutable. Knowing this, you should not grieve for the body."
a) Since we can't find or measure the soul by material means, the only source of information about the soul is the śruti, or Vedic wisdom. Just as one has to accept the identity of the father based on the word of the mother, there is no source of understanding about the soul except the Vedas.
b) The soul is conscious and at the same time consciousness since consciousness is the symptom of the soul. The soul is atomic and unchangeable, therefore the soul can't ever become equal to God.
« The Song of God: An in-depth study of the Bhagavad-gītā (Volume 1)