2.17 Know that the self in its essential nature is imperishable. The whole of insentient matter, which is different (from the self), is pervaded by the self. Because of pervasiveness and extreme subtlety, the self cannot be destroyed; for every entity other than the self is capable of being pervaded by the self, and hence they are grosser than It. Destructive agents like weapons, water, wind, fire etc., pervade the substances to be destroyed and disintegrate them. Even hammers and such other instruments rouse wind through violent contact with the objects and thery destroy their objects. So, the essential nature of the self being subtler than anything else, It is imperishable.

(The Lord) now says that the bodies are perishable: