Srimad BhagavadGita

So far, Kṛṣṇa stated with evidence that the soul exists forever, unlike the insentient body and one who knows this has no reason to grieve over it. The following three ślokas demonstrate abhyupagamyavādaṃ (taking up a purely hypothetical case for discussion). In this śloka, Kṛṣṇa explains to Arjuna that even if he believes that no separate soul exists beyond this body like an atheist does, there is still no reason for him to grieve. Kṛṣṇa says, "O mighty armed one! however, if you think that this soul always takes birth and always dies like the body, even then it does not befit you to grieve in this way."

atha manyase (However, if you are thinking that...) 

atha (however) 'atha' suggests that now Kṛṣṇa is taking up a view which is contrary to what HE explained so

far.   

manyase (if you are thinking) This may mean that Kṛṣṇa is questioning Arjuna if he thinks like that? or that

Kṛṣṇa is getting ready to prove HIS point from the perspective of dehātmavādaṃ (the doctrine that

body itself is the soul) too, if Arjuna believes in it.

atha ca nitya jātam, nityam mṛtam vā enaṃ manyase (If you are assuming this soul to be the body itself, taking birth always and dying always) 

vā The 'vā' has the same meaning as 'ca' which has the same meaning as 'eva'.    

nitya jātam nityam mrtam When a substance is said to be nityam (eternal), it cannot be having birth and

death. Hence these words of the śloka cannot be interpreted as, 'that which is eternal, having birth and

death'. It can also not be claimed that birth and death occur to the same substance always. Therefore the

appropriate interpretation for these words is, 'That for which birth and death are inevitable'. The body

alone has such characteristics. Hence it is the body which is being referred to over here. So the meaning is,

'O Arjuna, are you assuming this soul to be the body to which birth and death occur and not as a separate

eternal entity?'

enaṃ nitya jātam nityam mṛtam manyase (Not knowing that this soul is different from the body, if you are assuming it to be the body itself, taking birth and dying)

tathāpi Even if you are thinking in this way (that this body to which birth and death are inevitable, is the soul itself).

naivaṃ śocitum arhasi (It does not befit you to grieve a lot like this.) In the earlier ślokas, Kṛṣṇa explained that there is no need to grieve for the soul since it is indestructible,. In this śloka, Kṛṣṇa tells that even if Arjuna thinks the soul to be the body which is subject to birth and death, there is no need to grieve.

Reasons are as follows,

1)The body for which birth and death are inevitable is bound to undergo destruction. Such destruction can

cause some grief but not grief of this magnitude.

2)When the soul is considered to be different from the body, there is still a chance to grieve greatly that killing    acāryas may lead to our stay in condemnable places like hell after death of this body. In dehātmavādaṃ where body and soul are considered as one, there is no concept of hell or afterlife punishment and death of the body itself is the end to all the miseries of the world. Hence, there is no need to grieve greatly over death. On

the contrary, death should be a matter of great happiness as death of the body itself is liberation.

mahābāho tvam (You who is valorous) O Arjuna! You must conduct yourself in accordance with your own valorous nature and not grieve like this for your own death or the death of your near and dear ones.