The Yoga Sutras of Patanjali is an excellent text describing the practices of yoga and their culmination in Non Dual Self-awareness.
It is from Chapter 4, verses 4-6 of Patanjali’s Yoga Sutras.
[I]4. Individualized fields of being are brought into existence only from the sense separation, or notion “I am”.[/I]
The moment there is a sense of being separate, or a notion that “I am”, an individualized field develops. This is the root of all ignorance, that there is an “I am” separate from everything else. There is only the One Reality. When there is no question that all is the One Reality and it is experienced beyond words, the individualized field merges back into the infinite.
Realized teachers have encouraged their students to inquire into the reality of the sense of “I am”. They are encouraged to contemplate it until they know exactly what it really is. At the end of the inquiry, they realize it was a concept with no corresponding reality. Concepts do enable us to have experiences in time and space. They are as true and real as characters in a story book that exist only for the sake of the story.
[I]5. Although there is the sense of diverse activity, all individualized fields of being are motivated by the one un-individualized field.[/I]
At night when dreaming, there are many diverse characters, places, and objects within the dream. They all exist as manifestations of the dreamers psyche. They are non different from the dreamer. Similarly, all the diverse activities, points of view, and individualized fields of being are motivated and exist in and as the one infinite reality.
[I]6. Of the various activities, meditation results in non-accumulation of karma.[/I]
Karma accumulates when we are invested in and attached to the results of our actions. Attachment is like glue. It causes our ideas and concepts to stick to our awareness. Every action motivated by a compulsive need or desire to accomplish something, is one more attachment creating activity that builds up identification with a personality, our false sense of self.
Think of a goal you once had, how you identified with it so strongly, that it was all you could think about. Obstacles that arose to prevent that goal created even more passion to achieve and accomplish the desired end. As attachment and desire increased, so did your identification with a personality that needed to achieve something. When the goal was realized, your false sense of self grew stronger. “I achieved that!” If you utterly failed in your attempt, the false sense of self also grew stronger. “I failed miserably.” Through identifying with the varied actions of life, you build up the false sense of self, and perpetuate the delusion of being a limited human being.
Meditation properly practiced withdraws attention from identification with external phenomena. It creates space, so that we can step back and watch the wheel of life rotating. With this distance, we no longer add momentum to identifying with thoughts, actions, objects, etc.
Beginning meditators often feel that they are practicing improperly because their mind is still filled with thoughts, ideas, concepts, memories, etc. If beginning meditators could allow the thoughts, etc. to pass, remaining as a detached observer, then they are practicing effectively. In the beginning, watching thoughts pass, being aware of memories, or witnessing the fact that we feel like a separate entity from the universe, are all acceptable so long as we do not get pulled into identifying with those things. By remaining as the alert witnessing presence of all that arises within awareness eventually those changes and fluctuations will lose their momentum, and all that remains is the Self. Because of this, meditation does not lead to the accumulation of karma.
Also, remember that while practicing your daily meditation it is good to avoid feeling that you are doing something special. Otherwise, your meditation practice is then accumulating karma, as you are building up a sense of self by defining your self as a meditator.
Think of meditation as though it is as natural as breathing. We don’t walk around claiming we are breathers. Nor do we need to walk around dramatizing or proclaiming our spiritual practice. Keeping this in mind will prevent your spiritual path from turning into another karma creating personality centered activity.