In this spiritual hierarchy, from the grossest to the, subtlest, you are the subtlest. How can this be realized? The very base is that you don't know you are, and suddenly the feeling of "I Amness" appears.
The moment it appears you see space, mental space; that subtle, skylike space, stabilize you there. You are that. When you are able to stabilize in that state, you are the space only.
When this space-like identity "I Am" disappears, the space also will disappear, there is no space. When that space-like "I Am" goes into oblivion, that is the eternal state, nirguna, no form, no beingness. Actually, what did happen there? This message "I Am" was no message.