Ātmā is distinct from anātmā, it doesn't mean ātmā - me is here, but my body is hanging somewhere else. It means ātmā is not limited by anātmā although it appears as anātmā. I appear as this body now, but I am not limited by it. I am just awareness which exist before this body was born, during the body existence and after drop of the body. Just like clay exist all the time before pot come to the being, when pot is, and after pot is gone. Anything which comes and goes is asat which is nothing but name and form with its function. It is nothing but an idea which is knowledge itself. Without knowledge, nothing can come to being. The entire creation / manifestation is nothing but knowledge alone.
In our daily life we always understand knowledge as particularised subject matter. It is called visesajñānam - particular knowledge. There is another kind of knowledge which reference to awareness itself called avisesajñānam - knowledge as it is. When we see a pot, there is pot-cognition in my thought, therefore the pot-existence is recognized. Now we move our sight to the book, there is book-cognition in my thought, therefore the book-existence is recognized. The awareness of the pot is replaced by the awareness of the book. Between these two awareness, pot is gone, replaced by book, but the awareness is never goes. Even when there is no object of cognition, awareness is always there, just like in our deep sleep. When all the visesajñānam are negated, avisesajñānam continues to be. The awareness is always there /always exist, and because of the nature of its existence, it is called sat.
We were seeing how awareness is existence from the individual angle, and now we try to see how the existence is also awareness supporting the entire creation from the universal angle. Any product has two necessary cause, one is the efficient cause - nimittakāranam and another one is material cause - upādānakāranam. For example, clay is the material cause, out of which a pot-maker makes pot. The pot maker is the efficient cause, because he has the knowledge and skill to make the pot. Similarly in this creation, sat-existence creates the entire universe, he is the creator - efficient cause, but what is the material he is using for creation? If there is certain material outside of the creator to create this world, where did he get the material before the creation happened? If there is other thing outside of him, it should come from somewhere, and there must be a creator who create this material. There is no end in this way to find the ultimate creator. Therefore the material is not something outside of sat, it is the knowledge - cit alone which manifests into the entire universe. Just like our dream, knowledge alone manifest into the entire dream world, including the dreamer who are in the dream world. The existence of cit-knowledge is always there before the creation, after the creation, and after the resolution. At the resolution, all names and forms (entire creation) are resolved, left only the awareness / knowledge, just like in the deep sleep state, all the visesajñānam are resolved, left only the avisesajñānam - awareness per se. Therefore sat-existence which is supporting the entire creation is also cit-awareness/knowledge. This sat-cit-ātmā is me alone.
Let us go back to the topic of ātmā being eternal (before the discussion of sat). Ātmā was there before anything was there, including time. Now, we are trying to ascertain that time is asat having its dependency on sat-ātmā. What is time really? It is continue progress of existence in the past, present and future. When we say past was there. What can prove the existence of the past? Only if present is there. And what can prove the present is there? Only awareness is there. Similarly for the future. Time exist depends on the existence of awareness, therefore times is asat and awareness is sat. All objects in the world - anātmā are time-bound, because being born in time. Since time is having the nature of “changes”, therefore all things which are born in time also are having the nature of changes, including destruction. This is the basis to understand next verse.
acchedyo'yamadāhyo'yamakledyo'śoṣya eva ca |
nityaḥ sarvagataḥ sthāṇuracalo'yaṃ sanātanaḥ||2.24||
It is not subject to being cut, burned, wet or dried.
It is beyond time, all-pervasive, immovable, and immutable.
Any product is an assembled (put together) by parts. That which has parts can be cut and separated by weapon. Similarly water also can moisten something which has parts and become disintegrated. Air can dry up any gluing agent which brings parts together. Fire can burn only anything which has form. In here the five-elements model of the creation is taken up. From Tattvabodha we have learned that the world is made up of five elements: ākāśa - space, vāyu - air, agni - fire, āpah - water, and prthivī - earth. In the subtle and gross forms, these elements account for everything that is here. The subtle elements accounts for the mind, senses, etc and the gross elements account for the physical body and physical world. Except space, other four are having parts, therefore they can be modified. Even though space and time are part-less but as manifestation, one day they will also be resolved. Therefore the self is beyond time, beyond space (all-pervasive), immovable (movement required time and space) and unchangeable (change / modification is the nature of time alone).
This verse is the reason to establish next verse.
tasmādevaṃ viditvainaṃ nānuśocitumarhasi ||2.25||
This is not manifest (cannot be perceived), nor can this be thought of (as one thinks of an object); not subject to mutation either (because it is not born). Therefore knowing this Awareness to be thus, you have no cause for grief.
Vyakta refers to anything that is manifest, that which is an object of perception, object of the sense organs. And that which is not manifest, not an object of the sense organs, is avyakta - not manifest. Because it is not manifest, therefore we shouldn't find it in any perceived object when we hear that the "knowledge of the self frees us from sorrow".
Q: If self is not an object of perception, perhaps is it an object of inference?
A: No, ātmā cannot be an object of inference because it is not an object of thought. Whenever is the object of thought is the manifestation of the mind. From the experience of deep sleep we understand this point, because when mind is not there, the self is still there. Therefore self can not be thought of. Therefore self is not object of meditation, we cannot find the knowledge of the self through meditation.
Q: How can you say that self is not object of meditation. Isn't in meditation, we often being asked to focus on the self?
A: We just saw that self is not object of perception nor inference, where the mind should land on? We also have learned that the self-awareness-self is witnessing the mind, how can the objectified objectifies the objectifier?
The basic definition of meditation is when the mind stays on the particular object or subject matter in a length of time. When the mind is in this condition, we called it one pointed mind, which is the thought of mind being one pointed. When we analyze a "thought", it is always involved two knowledge / cognition. One cognition is with reference to the object called visesajñānam - particular knowledge and the other is with reference to awareness itself called avisesajñānam - knowledge per se. Therefore in vedanta meditation initial stage was focusing the mind in the certain object - visesajñānam, then bringing the attention of the understanding that awareness as it is - avisesajñānam is the support for any meditation object. This awareness cannot be the object of the mind, just like the light as it is cannot be the object of the sight.
This creation is nothing but from un-manifest to manifest, then go back to un-manifest alone, therefore knowing this awareness to be thus, you have no cause for grief.