All mystical traditions on the planet Earth use this technique of meditation on death.
Focus on fire rising through your form, from the toes up, until the body burns to ashes, but not YOU.
Katopanishad (sacred Vedic text) describes this technique wonderfully. I can say that the most used technique in Vedanta for enlightenment is this death meditation. Everybody, before taking sannyas, has to go through this technique. In Buddhism, anybody who is initiated into sannyas has to first go and sit in the graveyard for three months, continuously facing the dead bodies being burnt, while visualizing that he is also being burnt.
During my parivrajaka (spiritual wandering), I personally had this experience in Varanasi at Manikarnika Ghat, where they burn 300 bodies per day! When you continuously see this happening, you actually lose respect for death. Now you have too much respect, too many ideas about it. It is nothing! The breath which went inside did not come out. That’s all!
When I saw the bodies being burnt continuously, the little fear which was there initially disappeared and slowly, it became interesting. I began to go near and helped them. I started to think, “After all this body is also going to become like this. Yes. Over! Oh, God. Yes, in the same way this body is also going to burn. Let it happen.” That click opened up a deep fear of death which spread all over the body.
When the fear met my awareness, it became a death experience. I faced it consciously and could see the fear very clearly. Understand, whenever your fear is suppressed, it stays inside you as suppressed fear. When it comes out and you are not facing it consciously, it becomes a fear stroke, shakes and breaks your whole nervous system – you experience a nervous breakdown. If it is faced consciously, it becomes a death experience. I was able to see very clearly the body is dead. It was not moving.
Two and a half days – no food, no water, no thought, no questions. I could see with closed eyes that the body was dead and without movement. Suddenly that deep click and clarity happened – ‘The body is dead, but I still exist. I am here.’ Slowly I opened the eyes and was able to move the body. The first thing I felt was such a deep ecstasy, joy, gratitude – bliss! I knew I would not be alive any more as I thought, because the fear of death left once for all. I can say this is one of the very strong experiences that transformed me towards my enlightenment, towards the ultimate, spiritual truth.