[D6b2v1HA]

Hi loong

I think this question needs a standpoint. It's like the issue in relativity

theory. We need a stangpoint to look at what we're observing. And when

we talk about it we have to talk about it as it relates to something else.

We cannot talk about it without referring to another thing.
(for example the world is moving in such and such speed when compares

with such and such thing etc.)
Everything is impermanent because everything is changing. Still, there

are three kinds of change: nonchange, cyclic change and sequent

change. Nonchange is the "voidness" (or the "backgroung.")
However, when we look at voidness and talk about it, we have to talk only

it's void from anything when compares to another thing. Besides, it's the

background so there's nothing before the background. It's just a

reference point.
As for cyclic change, it's the recurrent change such as seasons. And

sequent change is the change that doesn't return to the starting point.

(children to old man and never return to children again.)
Therefore, everything is impermanent becuase they are changing. And

there's voidness in the background.
By the way, I believe "impermanent" in buddhism has less to do with the

change "without" but the change "within." Even everything is changing

(without) but if we know about this and our mind don't cling to that

changing, then we will not affect by them.

As for your question, "If everything is impermanent, what was there

before voidness?"
My simple answer is "Everything is impermanent becasue everything is

changing. There was nothing there before voidness because voidness is in

the background of everything that is changing (impermanence.)"