' koong ' means everything in this universe is impermanent/temporary, ' sa na sa na ' all existed in a matter of 0.0000 - - - - - - - - - 000 second ie it is insignificant/negligible in terms of times when compared to our pure mind/true mind or our true self/true nature which exist permanently/ eternity/ no birth no death . We, everyone has a permanently alive functioning ( chuh sze chien fa ) mind aka pure mind . We also have a false mind ( existed temporally ) that function in this mundane world ( ' sze chien fa ' ) . Pure mind and false mind coexist ( pure mind exist eternally but false mind come and go/ got birth death, death birth repeatedly. Pure mind produce/give birth to false mind ) . When we die, unconscious, sleep, our false mind disappear, die , vanish. We do really has existed in this world, but temporary/insignificant time frame aka ' sa na sa na ' when compared to eternity ie life span of pure mind . Using physical ear or eyes to hear pure mind / to see pure mind is impossible . Must use our mind to see, ie use ' hui yen/ wisdom eye to see. Mind verses mind only compatible or same frequency only can see. Actually BUDDHA teaching is very scientific, lt is science, everythings in this universe exist and function base on science. Nothing can escape from science !! 2500 years ago, before Buddha came to this world , science was very very backward. That is why it is very very difficult to explain and write Buddha's teaching in words. There was no words/ languages/sentences to explain Buddha's teachings in an understandable way. Therefore there are many type of explanation on Buddha SUTRA . This explain why the phrase appears ' yen chiey lu lai chen sze yie ' Hope l am right