1.13 Chapter 1 Verse 13 - Astavakra Geeta - illusion of 'I'
Meditate on unchanging, conscious and non-dual Self. Be free from the illusion of 'I' and think this external world as part of you . ॥1.13॥
Who I am? is the most important question in the spirituality. What we consider as "I"is the bunch of thoughts, which keeps on changing right from the birth to the death. But the bunch of thoughts is the higher level over the basic "I am"which never changes. Therefore we get the impression of continuity in "I am". The continuity which is provided is not the bunch of thoughts which we consider "I", but it is the basic, non changing "I am", the consciousness, the wholeness.
When we are born, the upper level of "I am" starts conceiving, starts formulating. Initially our thoughts says "I am a child". Slowly as we grow, our thoughts say "I am a girl" or "I am a boy". Then subsequently the upper layer of "I"thoughts keeps on changing from, "Youth", "Student", "brother of","sister of", "parent of", "owner of", "an aged one"etc. At some point we may have simultaneous multiple identities like "I am male" "I am doctor", "I am parent "etc. But since basic, root "I am" feeling which never changes, gives the continuity to the the bunch of thoughts "I am".
How can I be which keeps on changing. So if we decide to find out the one "I"which never changes in us. The bunch of thoughts always keeps on changing, therefore I cannot be the one "I ""think". Then can I be body and mind, which seemingly does not change. But if we see carefully, we will see that, the identity of "Body and Mind" also keeps on changing from various phases like "child", "young", "an aged one" etc. Therefore body and mind can't be "I am". The real "I am"must not change during its journey.
Then, if we consolidate on ourself, meditate on ourself, we will find that there is only one thing in us which never changes. Its our consciousness. It keeps on shifting from one thing to other, one object to other, but it never changes. It does not change age wise. It is constant all the time.
If we think of an external world, the objects of external world are in fact comes into being when they are thought upon, when they are brought under consciousness. Rest of the time, it is as good as the world does not exist for us. It comes into being only when we shift our consciousness to it. Therefore since the existence of the world depends on consciousness, we can say external world is also consciousness. And as consciousness is "I am", we can say external world is also "I am".
And as this consciousness is shared by all of us, it is non-dual.