Chapter 2 Verse 23

nainam chindanti sastrani nainam dahati pavakah

na cainam kledayantyapo na sosayati marutah

sastrani – weapons

enam – this ( the self )

na chindanti – do not slay

pavakah- fire

na dahati – does not burn

apah- water

kledayanti – do not wet

marutah ca – and the wind

na sosayati – does not dry

Weapons do not slay the self nor does fire burn it.

Water does not wet nor wins dries it.

In this verse krishna mentioned a few methods of destruction none of which affects the atma. Consciousness has no form. If it had a heart it could beat but it does not have a heart. But our heart beats because if the atma present in the deha. Atma is the subject of every object. So weapons cannot harm it. Fire cannot even burn the sukshma sharira let alone atma. Like wise the atma cannot be drowned in water nor dried with wind. In short atma is beyond all the sensory perceptions.

Our physical body comprises of 5 gross elements. It contains vayu agni space a paha and the minerals found in earth. These make up our body. Like wise the universe is made of five elements. Only objects belonging to the same order can affect each other. E.g a body and weapon both are physical objects. So they can harm each other.

But can a weapon cut through space or air? No. Because they are of 2 different orders. Space cannot be destroyed by bombing or shot with a pistol. It cannot be even polluted. We don’t say space is polluted but we say the atmosphere is polluted.

The atma does not have any limbs attributes or structure. It is pure consciousness which pervade entirely. Atma also does not belong to the same order as our body nor the physical world. So how can death be possible for the atma? We gave to shed our dehatma buddhi and develop ishwara buddhi. Ishwara is you and there is no other ishwara outside.

Can a wave in an ocean call it as I am tge wave and don’t belong to the ocean? No. The wave can be a big , small or a tsunami. But it’s identity is with the ocean. Like wise if we think we are just body mind sesnse then we are deluded. We are more than that. If the water in the ocean dries off can there be waves? So it’s just the nama rupa that differentiates between bodies. E.g male , female, young etc. But atma does not have any name form etc. We don’t call atma as male female etc. Atma is just atma.

The teaching here is to understand the limitations of having just view ourselves as just physical body. But we are the consciousness and shuddha Caitanya. Nothing can affect as it is the ultimate witness to all the senses.

In Mandukya upanishad the concept of the 4 states is explained so also in drg drsya viveka. In deep sleep state do we know if we have a body? No. But when we wake up every day our atma tells that we slept well or we didn’t. We don’t see or experience any thing because our sense organs are dormant. That’s why the sleep date is related to as good as dead. So we wake up and take a shower first thing and then do the rest.
Krishna says in a later chapter that

vimooda nanu pasyanti pasyanti gnana cakshusha ha

Deluded people who still have the ego or the concept of ‘I’ cannot reach me. But people who have left their ego I.e I’m the doer, I’m the body etc. They will attain me through gyanam and surrendering all actions to me and not get associated with the results.