Sage Sankara says: the idea that the external world exists, won't go. It can go only by an inquiry into the nature of the external world.+

The Yoga Sastras say that the Sahasrara or brain is the seat of the Self. The Purusha Sukta declares that the Heart is its seat. When the ‘“Self’’ not the body then why you are thinking of the brain and the heart.   The Soul, the 'Self’ is ever formless, timeless, and spaceless existence.  The Soul is not within the body but the world in which you exist is within the Soul. 

When you realize the world in which you exist is created out of the Soul, which is present in the form of consciousness then you will realize the world in which you exist is merely an illusion created out of the Soul, which is present in the form of consciousness.

That is why Sage Sankara:~  VC~.63: "Without knowing and examining the external world, one can’t know the Truth, as the idea that the external world exists, won't go. It can go only by an inquiry into the nature of the external world.

Mundaka Upanishad 1.3:~ Complete knowledge includes knowledge of the phenomenal world, the spirit behind it, and the source of both of them.  When the cause of all causes becomes known, then everything knowable becomes known, and nothing remains unknown is Gnana.”

It takes time for the seeker to gain the perfect understanding of ‘what is the truth’ and ‘’what is untruth’

Sage Sankara says: ~Yoga is not the means of liberation (pages 132-133 of his commentary on Brhadaranyakopanishad).

Bhagavan Buddha gave up yoga after practicing it for six years. He saw it could not yield truth. 

Bhagavan Buddha gave up his austerities of yoga as impossible and useless. Thus Bhagavan Buddha got enlightenment only after he gave up Yoga. (Page.70/71 "Buddhism in Translation” by Warren)

Ashtavakra says: ~ “This is your bondage, that you practice Samadhi or meditation.”

Meditation is not the means to “Self’ –Knowledge or Brahma Gnana or Atma Gnana. Meditation is not the goal itself. It is an important and useful tool to quiet the body, mind, and emotions and allow one to enter a deep and quiet state of mind. Once the turbulent tendencies of the body or ego and emotions are brought into harmony, clarity and renewed strength are available to meet and overcome each life challenge as it presents itself. Meditation will not eliminate our life challenges but can enable us to harmonize our body, mind, emotions, and spirit and to focus that energy like a powerful beam of light on the challenges that lie ahead in worldly life. 

When one sits down to meditate, he is thinking first of sitting, i.e. his body; then he tries to have only the thoughts of getting rid of the thoughts, with the thoughts of getting rid of the thought.  Thus, he is thinking as a person within the world.  Thus, he remains a person practicing meditation, thinking the ego alone is illusory, and the rest (universe) is a reality within the illusion.  He only thinks of the object, within the object, as an object.  But he is never aware of the formless subject.  : ~ Santthosh Kumaar