Yoga Sutras of Patanjali 1:18: By the firm practice of the cessation of the mental modifications(right knowledge, misconception, verbal delusion deep, sleep memory), the impressions only remain. This is the other samadhi (objectless samadhi).
Go here for more in depth information on the mental modifications and objective Samadhi.
Defining the Sutra
In this form of samadhi, you are totally liberated and free from the mental modifications. They don’t pop into your mind anymore. You are jivanmukta, liberated while still alive. Many spiritual teachers view death as the great letting go. Many people will not let go of the false self until they are forced to through death. To be jivanmukta is rare.
Modern Day Application
I recently wrote an article on why it is important to be uncomfortable in yoga. While there is definitely benefit in taking a chilled out yoga class to relax or using yoga therapeutically to heal injuries, the final stage of yoga is objectless samadhi. It is the ability to be in any environment and still be free. Yoga is the training ground for this.
Why It is Important
Are you a yogi on the mat but a jerk in the streets? It is easy to be a good person when you are in the controlled environment of a yoga studio or when everything is going your way. Who are you when you walk out of the yoga studio and your teacher or students are not watching? Do you lose all your zen the minute someone cuts you off in traffic as you leave the yoga studio? Who are you at work? Do you turn into someone who will manipulate your way to the top by any means necessary or a sleep walking zombie? When ish hits the fan and your life turn up side down, do you still talk with sweet words or do you lash out or withdraw? How do you treat people in your life who can do nothing for you? Do you smile at your boss while frowning at the waiter or homeless person you pass by? All of these are pointers. When you witness them in your life, you know there is still work to be done and the mental modifications are still in play.