The Yoga of Knowledge

After distinguishing the real from unreal in verse 16, Krishna reveals what that 'sat' actually is: consciousness that pervades everything (tatam). Like space contains all objects yet can't be destroyed, consciousness holds all experience yet remains untouched. You can damage the eyes reading this, but can you damage the awareness itself? It has no parts to break. This is 'avyayasya'—the immutable reality. Your deepest identity isn't your vulnerable body or mind, but the indestructible awareness experiencing them.