One who knows the true nature of Ātman understands that it is unborn, eternal and imperishable. Birth and death belong to the body, not to the Ātman.

शस्त्राणि (śastrāṇi) = weapons
छिन्दन्ति (cindanti) = cut
Meaning, weapons cannot cut the Ātman.

Krishna says that the Ātman cannot be cut by weapons, burnt by fire, wetted by water or dried by wind. These are all physical forces, whereas Ātman is not a physical object.

The analogy makes a subtle Vedānta teaching easy to understand:

Old clothes → discarded
New clothes → worn

Similarly:

Old body → given up
New body → taken

The wearer of the clothes is not the clothes themselves, just as the Ātman is not the body.

नश्वर (naśvara) means perishable. Ātman is exactly the opposite — it is imperishable.

Krishna describes Ātman as:

अव्यक्तः (avyaktaḥ) – unmanifest
अचिन्त्यः (acintyaḥ) – inconceivable
अविकार्यः (avikāryaḥ) – changeless

This is an important Vedānta distinction. The body is continuously changing — childhood, youth, old age, etc. Yet the consciousness that knows these changes remains unchanged. That changeless consciousness is Ātma.

शोष (śoṣa) means drying. अशोष्यः means that which cannot be dried.

The primary goal is to shift one's identification from physical body - mind to the Atma. While this is difficult it is described as the biggest and important shift for a seeker.

Dharma is the changeless values of life and Brahman is the changeless truth of life.