Master Chen talked a little about intention. He said when you are in contact with the opponent there is equal compression on both you and the opponent, just like Newton’s law which states that every action has an equal and opposite reaction. But, for example when you a nail with a hammer the nail goes into the wood. In this case the outcome is determined by the intention of the hammer to pound the nail into the wood.
An example is when Master Chen uses his opponents punch to bounce them out. When the opponent punches he sees the fist as a static object and he hits it with his chest. But if there is any hesitation, if he is scared at the last moment, then it hurts his chest. If not then his chest is fine but the fist gets hurt. He says that this is intention.
Intention cannot be taught or learned. It is like you practice and practice and then one day you do it and then you say to yourself “oh, so that’s what intention is.” Until then we can’t really understand what it means.