All the different forms of external yoga practice must be accompanied by the internal yoga practice of annihilating egoism of attachment, identification, craving, aversion, judgment, comparison and expectation, supported by the internal mental strength, flexibility and stamina of patience, perseverance, determination, tolerance, forbearance, acceptance, adjustment, adaptation and accommodation, as well as cultivating the essential tools for self-inquiry and self-realization, such as awareness, dispassion, desireless, renunciation, self-discipline, self-reliance, seclusion, solitude, care-free, fearlessness and equanimity, to be efficiently purifying, calming and quieting the impure egoistic restless mind, to prepare the mind for spontaneous meditation into Silence (complete annihilation of the mind/birthlessness and deathlessness/attributelessness, namelessness and formlessness/oneness or non-separateness).
Even if one’s physical body is unable to perform any external yoga practice, it doesn’t stop the mind from performing internal yoga practice to annihilate egoism, impurities and restlessness, and be free.
Without the internal yoga practice of annihilating egoism and impurities which is nothing to do with the impermanent and selfless physical and mental condition, ability and limitation, the mind will always be disturbed by the mind perception of names and forms of all kinds of pleasant and unpleasant, desirable and undesirable, agreeable and disagreeable life experiences, where there’s clinging and craving towards pleasant/desirable/agreeable experiences and aversion towards unpleasant/undesirable/disagreeable experiences, even after many years and huge amount of external yoga practice that one has been performing or many years of teaching yoga and meditation practice to many other people, and getting all the momentary effects and benefits from the regular external form of yoga practice.
The mind might be rendered calm and quiet momentarily during and after all those external yoga and meditation practice, but it doesn’t last long, as very soon, the mind would unwittingly slip back into restlessness due to the stubborn egoistic mind habits of chasing after the objects of the senses, worldly enjoyments and stimulation, passionate desires of worldly and/or spiritual aspirations and ambitions, worldly social interactions and activities, and the ceaseless impurities generated through countless actions and reactions towards the mind perceptions of names and forms due to egoism of attachment, identification, craving, aversion, judgment, comparison and expectation, where the mind is restless most of the time, even if the mind can attain certain degrees of relief from restlessness for a short period of time during deep sleep state, or during and after the different forms of external yoga practice.
By freeing the mind from egoism would allow the mind to be undetermined or undisturbed by the mind perception of names and forms, of quality and duality, or the good and bad/positive and negative/pleasant and unpleasant/desirable and undesirable life experiences, that allow the mind to be free from impurities and restlessness thoroughly.
And hence, the importance of the practice of silence for those who truly want to conquer the restless modification of the mind, to attain Silence.
After some time of practicing some kind of yoga and meditation practice regularly, one needs to perform self-introspection, “Is the mind still being determined or affected by the impermanent and selfless physical and mental condition, ability and limitation, as well as the worldly affairs, relationship, friendship, social activities and interactions, and worldly and/or spiritual achievements and acknowledgements to feel good, confident and meaningful, or not?” and “Is the mind still being determined by duality of good and bad/positive and negative/right and wrong/meaningfulness and meaninglessness/happiness and unhappiness, or all the mind perceptions of different qualities of names and forms, to feel good, positive, rightful, joyful and meaningful, or not?” or “Is the mind still being disturbed by what the mind thinks and believes as bad, wrong, negative, unhappiness and hurtful?” If the answer is yes, it means the mind is still not free, even if one has been performing yoga practice for a long time, or possessing many ‘yoga certifications’, and believing in ‘goodness’, ‘righteousness’ and ‘positiveness’.
It’s everyone’s freedom for what they want and don’t want to practice.