Firewood does not turn into ashes! 
As Zen Master Dogen said, "... we should not take the view that
what is latterly ashes was formerly firewood. What we should
understand is that, according to the doctrine of Buddhism, firewood
stays at the position of firewood.... There are former and later
stages, but these stages are clearly cut."
Every moment is complete and transient, yet unmoving. Changing,
changing, yet complete, unmoved. Drop the observer, just the
walking, the typing...
But there is no sense of walking while walking, no moving in
movement... everything is complete as it is, just This.
...Theres no mind for motion to
exist apart from, and no motion for mind to exist apart from.
Motion is the minds function, and its function is its motion. Even
so, the mind neither moves nor functions, the essence of its
functioning is emptiness and emptiness is essentially motionless.
Motion is the same as the mind. And the mind is essentially
motionless. Hence the Sutras tell us to move without moving, to
travel without traveling, to see without seeing, to laugh without
laughing, to hear without hearing, to know without knowing, to be
happy, without being happy, to walk without walking, to stand
without standing...
THE ZEN TEACHINGS OF BODHIDHARMA