To come to the insight that you are not the body you first need to find out what the body really is. The body must become an object of perception rather than just an idea. In most cases when you refer to your body, you are referring to an image constructed at some time in your life, a pattern you’re accustomed to assuming is your body. But when you stop projecting this pattern and allow the real body to speak, you feel all its tension and heaviness. In the very act of clearly seeing the habitual ideas you have taken to be real, you stand removed from them, and cease to be an accomplice with the old patterns. You come to the original body sensation: an emptiness without border or circumference. You feel the body to be completely extended in space.
But the body itself isn’t a problem. Feeling the real body, the body as it is, helps you discover a way of looking without projecting. It takes you beyond the body and a moment comes when localization ends and the energy previously fixed as “body” dissolves into listening itself. In other words, because there is no longer a fixed listener or something heard, the subject-object relationship drops away. There is only oneness.
From The Ease of Being, pages 49-50
You can read more from Jean Klein here.