Pushing pain, for those of you who don't know what that means, is sitting still regardless of any pain and just trying to go, go, go for a certain amount of time. "I am going to sit still for two hours. I am going to sit still. I am going to sit still." The danger of pushing pain is you can tear the tendons in your knees, you can tear your ankle tendons. We know people who have done this by pushing pain. Also another danger is the ego, "I am a person who can sit still for 2 hours, I am better than you are." There is danger in that. So, on the physical level there is danger, on the mental level there is danger.
To know the difference between meditation pain and real physical pain, how can you recognize the difference, the border? Change your posture, see if it goes away. If it goes away then it is only a meditation pain, the next time it comes you can then work with it with the meditation techniques. Now as to pushing limits, that is different to pushing pain. The techniques that I give in the Unpleasant Physical Sensation talk on the fourth night, with those techniques we are going to push limits by staying still. But it is different to pushing the pain, "I am going to sit here although it hurts and it hurts and it hurts. I am going to be tough, I am going to sit here although it hurts." That attitude is very different to trying to see the sensation as a sensation, seeing the size, the shape, etc. When we do this, we are doing it in an interested way, we are doing it in a way that is soft and gentle. That is very different to the attitude of the ego when we try to push pain.