Any gaining / reaching is preceded by action / journey (time). When we want to obtain something, we need to certain action to get it. When we want to reach somewhere, we need to do action of going to reach there. When someone wants to be free from jail, he/she needs to wait for the time journey to get the physical freedom. In the case of freedom from samsāra, the only way is to know my real nature as limitless ātmā. There is no action to be done for us to own up this freedom. The only way to be free is to know that I am ever free. The mean for liberation is knowledge. And means to get this knowledge are śravanam - listening to the teaching of Vedānta, mānanam - resolving any doubt toward the teaching, and nididhyāsanam - meditate / contemplate on the teaching.
Next, we will get in to the topic of meditation as the means for abiding in this Self-knowledge. As Vedānta students, we have studied and understood well that I am saccidānanda ātmā, the basis of the entire creation, everything exist depend upon me, my limitless nature doesn't depend on any other thing. But how come sometimes we just can not see this fact in our day to day life, and we are still emotionally being dragged into the up and down of this experiential world? Because we have not assimilate the teaching / fact well. This ignorance about the self have been with us since time beginning-less and causing all the habitual error in our lives, how all these wrong habits can be removed in once after the raise of knowledge? We can not say there is no possibility for this kind of case, but it just happened for uttama-adhikārī - a highly qualified student who endowed with full fletch of four folds qualification. But this case is rare. Most of us need to assimilate / internalised this teaching in to our life. This is called nididhyāsanam. This internalisation is done by dwelling on the teaching as often as possible. This process of dwelling on the knowledge can be done several ways. Repeated śravanam is one of the method. While listening to the teaching , we need to convert the word Brahman or Ātmā to "I". Another method is to dwell on the teaching exclusively in an appointed time. During this time I should deliberately withdraw from all transactions and the roles which evoke I-ness, and only evoke my true nature, which usually called as meditation.
From verse 22nd to 31st, acārya prescribed six types of meditation which is called samādhi here.
upekṣya nāmarūpe dve saccidānandatatparaḥ । samādhiṃ sarvadā kuryāt dhṛtaye vā'thavā bahiḥ II 22 II
Being indifferent to both name and form, and devoted to the Truth, one should always practice meditation both in the heart and outside.
Nididhyāsanam is Vetāntic meditation which dwells upon the teaching intently without trying to be thought-free. In here physical posture is not a primary component, we can adapt to any posture which help us to be physically relax yet mentally alert. One even can do nididhyāsanam while walking, eating or any activities, but one need more effort and alertness not to be dragged into the activities, instead of dwelling upon the teaching. One very important thing we need to put in the mind is that meditation will not giving me freedom (release me from samsāra), but I am claiming the fact that I am ever free. It is a tool for us to claim my ātmā-svarūpa (true nature) intimately, so i can removed my habitual error of claiming all the non-self as myself.
First the samādhi - meditation is divided in to internal and external.
In the meditation, one should focus the mind on the nature of saccidānanda - existence-consciousness-limitless I am. Even though it is always seen together with name and form, but name and from is negate-able. In this point we always have to remember verse 20th. This mixture is meditated upon by focusing on the changeless asti, bhāti, priyam and ignoring changes nāma rūpa.
This meditation is done two ways, one is close eye meditation and another one is open eye meditation. In close eye meditation, one mediate on any internal object, which is our thought. Every thought has the five components, the saccidānanda is focussed on and ignoring the name & form. For open eye meditation , one only focus on the changeless saccidānanda of the seen object.
Next the internal meditation is divided to further two kinds.
savikalpo nirvikalpaḥ samādhirdvividho hṛdi । dṛśyaśabdānuvedhena savikalpaḥ punardvidhā II 23 II
With attributes and without attributes – thus the practice of meditation within is of two kinds. Associated with the seen and with words – thus the practice with attributes is again of two kinds.
The internal meditation is further divided into savikalpa - with attributes and nirvikalpa - without attributes. The savikalpa-samādhi itself again being divided into two, one is associated with an object, and the other associated with the Vedāntic word.
In savikalpa, some support is used as an aid, just like using the hand for mediation upon the light. Light by itself is not perceptible, but using the object where light fall into as a medium to aware of the existence of the light. Unlike in nirvikalpa, there is no support for the meditation upon my own true nature.
Next six verses described how six kinds of meditation are to be practiced.
kāmādyāścittagā dṛśyāh tatsākṣitvena cetanam । dhyāyeddṛśyānuviddho'yaṃ samādhiḥ savikalpakaḥ II 24 II
Thoughts like desires, etc, arising in the mind are the ‘Seen’; as their witness, being oneself the Consciousness, one should meditate. This, associated with the Seen (cognizable object), is called “Meditation with attributes with the Seen.”
In this meditation, one puts the attention upon consciousness as the witness of thoughts. The consciousness principle is the illuminator or witness for the thoughts which are coming and going. Those thoughts can be in the form of objects, situations or even desires. Just like on the stage of the theatre which is always lighten up by a light principle, but light itself is never been noticed on the stage. It is always missed. Focus is always on the actors/actresses, their costumes, accessories or even background decoration, but just never on the light as the illuminator which makes them evident. The illuminator is called as sāksī - witness because even being exist together with all which are on the stage, but while they arrive and depart (go through all the changes), the light principle is always unchanged. And this unchanged light principle is what we should focus on. Similarly while thoughts arrive and depart, changing from one thought to another one, but we just focus on I - consciousness as the witness of all thoughts. This is attributed meditation through the thoughts which is seen.
Next is attributed meditation through words.