Abhyasa Yoga-Bhagavad Gita Chapter 6 [The Science of Self Realization]
Krishna Said > Shaloka: 25
Gradually, step by step, with full conviction, one should become situated in trance by means of intelligence, and thus the mind should be fixed on the Self alone and should think of nothing else.
By proper conviction and intelligence one should gradually cease sense activities. This is called pratyahara. The mind, being controlled by conviction, meditation, and cessation of the senses, should be situated in trance, or samadhi. At that time there is no longer any danger of becoming engaged in the material conception of life. In other words, although one is involved with matter as long as the material body exists, one should not think about sense gratification. One should think of no pleasure aside from the pleasure of the Supreme Self. This state is easily attained by directly practicing Krishna consciousness.