Srimad BhagavadGita

After speaking about the eternal nature of the soul in śloka 2.17 avināśi tu tad viddhi..., to establish this fact strongly, in this śloka Kṛṣṇa declares all those who do not know the eternal nature of the soul, to be ignorant.

Kṛṣṇa said, "One who knows this soul to be a destroyer (who destroys with the means like fire, weapons, etc.) and also one who assumes that this soul is destroyed (by another soul or any other means like fire, weapons, etc.) are both ignorant. This soul does not slay with means like fire, weapons, etc. and this soul is also unslayable.

The śloka nainam chindanti.. B.G 2.23 where Kṛṣṇa is going to explain that the soul cannot be destroyed by fire, weapons, etc, is an extension of the present śloka.

enaṃ (kamapi) hantāram yaḥ vetti (The one who knows the soul as the destroyer) Here appending the word 'kamapi- any destruction causing substance', helps in bringing out the meaning of the sentence more clearly. The meaning of this phrase is, 'one who thinks that this soul can destroy with the means of destruction like fire, weapons, etc.'

enaṃ (This soul) 'enaṃ' refers to this soul which is proved earlier to be eternal/indestructible

śloka).

yaḥ ca enaṃ hatam manyate One who thinks that this soul can be destroyed by any means of destruction like fire, weapons, etc.

ubhau tau na vijānītaḥ One who thinks that the soul can destroy and one who thinks that the soul is destructible, both of them are ignorant of the reality. 

ayaṃ na hanti As proved earlier with reasons, since the soul is eternal, it cannot be destroyed by any means of destruction like fire, weapons, etc, by the will of another soul.

ayaṃ na hanyate For the same reason (its eternal nature), it is implied that the soul is indestructible.

Since hanti and hanyate convey different conditions, when the same word 'ayaṃ' is paired with hanti it refers to 'the tools of destruction like fire, weapons, etc.' and when it is paired with hanyate it refers to 'the soul'.

This śloka makes the point that the soul cannot be killed by weapons, fire, etc.

An objection can be raised on this.

Objection: The above statement cannot be accepted from both worldly as well as the vedic view point. In this world, we come across the usage of statements such as 'I am killing this manuṣya (person)'. In the śāstras we see many statements such as na himsyāt sarvābhūtāni (No living being should be harmed) and brāhmaṇo na hantavyaḥ (Brāhmaṇa should not be killed). Here if the terms manuṣya, bhūtāni and brāhmaṇa are considered to be referring to the particular bodies alone, then even while stabbing the body of a dead person the same statement 'I am killing this manuṣya' will have to be used. But such usage is not seen. As per our doctrine, words like manuṣya, etc, refer not just to the body but also the embodied soul. So it will have to be agreed that the soul has the characteristic of being killed. 

Answer: It is true that the soul is the target of killing. But in the general usage manuṣyaṃ hanti (He is killing the manuṣya) there arises a need to scrutinise the meaning of the root verb 'hanti' used here to show the act of killing. The word hanti does not mean the destruction of the soul's swarūpa (inherent nature consisting of characteristics specific to it which never change) but tells only about the death of the manuṣya. Saying 'manuṣyaṃ hanti' means that he is causing the death of the manuṣya and causing death means separating the soul from the body. The mṛn prāṇatyāge dhātupātha (dhātupātha is a collection of root verbs with their meanings in Sanskṛt) also fortifies this meaning. Hence, in statements such as 'I am killing this manuṣya', 'Bhūtas should not be killed' and 'Brāhmaṇa should not be killed', the word killing is used in the sense of separating the soul from the body. In the statements ayaṃ ātma na hanti (hanyate), the verb form hanti (hanyate) is used to refer to the destruction of the soul's swarūpa. As the soul's separation from the body can happen and destruction of the soul's swarūpa can never happen, there is no contradiction in both the usages of hanti as manuṣyaṃ hanti and ayaṃ ātma na hanti.

A few more doubts that can be raised in this context and their clarifications are listed below.

Doubt: In the vedic statement na himsyāt sarvābhutāni, killing of any living being is prohibited. In another vedic statement agnīṣomīyaṃ pasumālabheta, killing of a living being is prescribed for the agnīṣomīya yāga. How can this contradiction be reconciled?

Clarification: The pūrvamīmāmsakās (those who are learned in the philosophy based on the earlier part of the vedas) reconcile this by saying that the statement na himsyāt sarvābhutāni is an utsarga or rule statement and the statement agnīṣomīyaṃ pasumālabheta is an exception statement. The rule statement condemns every animal slaughter and the exception statement allows the animal slaughter prescribed in the agnīṣomīyaṃ statement. This is called utsargāpavāda nyāya. Our ācāryas reconcile this contradiction in another way too which is as follows. An act which ends in pain is violence. Though a doctor's surgical procedure causes pain initially, it causes relief in the end, hence it cannot be termed as violence. Similarly, in a yāga though the slaughter might cause pain to the animal in the beginning, the animal rejoices in the end upon gaining access to heavenly abode. Hence the prescription in the agnīṣomīya statement cannot be considered as animal violence at all. Our ācāryas conclude that thus there is no contradiction here.

​Doubt: Our present śloka of the Bhagawad Gītā is similar to the mantra hantā cenmanyate hantuṃ hataścenmanyate hatam, ubhau tau na vijānīto nāyaṃ hanti na hanyate Kaṭha Up 1.2.19 (The killer may think that he is killing and the one being killed may think of himself as being killed. Both of them are ignorant. Neither is the first one killing nor is the second one being killed). In both, the Kaṭhavalli mantra and the present B.G śloka, though the 2nd line is the same, in place of the 1st line of the mantra hantā cenmanyate hantuṃ, this Bhagawad Gītā śloka has ya enam vetti hantāram. Keeping this difference in mind, the meaning of the first part of this śloka should be interpreted as 'One who thinks of this soul as the killer'. Even in Sribhāṣyam (Sri Rāmānujācārya's commentary on the vedānta sūtras), in the chapter kartā śastrārthavatvāt for the mantra hantācet...2.3.33, the same meaning has been given. Then for this particular śloka, instead of giving the meaning for 'ya enam vetti hantāram' as 'one who thinks of this soul as the killer', what is the reason for giving the meaning as 'one who thinks of fire, weapons, etc, as the killers of the soul?' This is the doubt that is raised.

Clarification: There is no debate on the fact that this Gītā śloka is an upabr̥hmaṇaṃ (elaborate explanation) of the Kaṭha upaniṣad mantra. It cannot be called an upabr̥haṇaṃ of the upaniṣad if it conveys the meaning in the exact same manner and detail as the upaniṣad. An upabr̥hmaṇaṃ is one that explains the meaning in greater detail. The upaniṣad is instructing that it is not possible for one soul to kill another soul. This Gītā śloka elaborates on the same by stating that, 'It is not possible for fire, weapons to kill the soul'. Following are the reasons for this elaboration,

1)In this world we see many destruction causing substances like weapons, fire, poison, etc. Common man may doubt that though a soul cannot be killed by another soul, an insentient substance can possibly kill it. In reality these substances cannot go and cause destruction all by themselves as they are insentient. It is the sankalpa (will) of an embodied soul to destroy, which makes his body execute it using a weapon, etc. However, this whole process only causes destruction of the target soul's body. The soul moves out of the destroyed body and continues its journey by taking up another body suitable for the experience of his karmas. In some instances, we see that natural calamities due to unseen forces of nature or the devatas cause huge destruction of life. In such cases too, death and destruction occur to the body only, forcing the soul to condemn the body and move out of it. Even when the embodied soul resolves to kill itself, all it can do is to destroy its own body and move out of it. Thus, it is always the body that gets destroyed either due to weapons or natural decay but never the eternal soul. Gītācārya Kṛṣṇa explains the same through this śloka as ya enaṃ vetti hantāram...(one who thinks that insentient substances like weapons, fire, knife, etc, can kill the soul or that the soul can be destroyed in any other way, is ignorant for sure) Like the tiny amount of ocean water that fits into a cow's hoof print, the upaniṣad meaning is also embedded in this śloka.

2)Also, seeing the word hantāram (killer) the desire to know 'the one who is killed' may arise. 'enaṃ' (this soul) is the answer to it. In the upaniṣad mantra, the word ātmānam had to be assumed. Here, in this śloka there is no need to assume.

3)Moreover, as Arjuna expresses a doubt in this chapter whether weapons, fire, etc, can kill the soul, it is necessary to clear it by instructing Arjuna that they cannot kill the soul. This will be elaborated further in B.G 2.23.