What is called 'entering the stream' is passing away with all things. The state in which all things exist is passing away in each moment - coming into existence and passing away instantly.

To exist in our original state, that of the instantaneous universe from which we are not separate, coming into existence and passing away in each instant, is the practise of Buddhas. Buddhas are nothing but existence passing away in each instant. Each instant of existence is nothing but Buddha passing away.

An experiential name for this could be unhindered awareness where no perspectives are held, nothing is held. The proprietary 'self' and the universe of meaning it inhabits that we artificially create has completely vanished into experience.

Passing away is also a description of activity in zazen, sensations arise and we let them go, thoughts arise and, if we allow them to, also pass away.

If we practise passing away, we become passing away.