It is quite easy to understand that there are things that are shaken -- things that have been made (and probably imperfect) on earth. The Lord promised to utter his voice and cause them to shake and be removed (Hebrews 12:26). But the reading of verse 27 got me thinking:

> 
> At that time his voice shook the earth, but now he has promised, “Yet
>  once more I will shake not only the earth but also the heavens.”
>  (verse 26 ESV)
> 
> 
> This phrase, **“Yet once more,”** indicates the removal of things that are shaken —that is, things that have been made—in order that the
>  things that cannot be shaken may remain. (verse 27 ESV)
> 
> 
> 

Are there things that are imperfect in heaven that the Lord has promised to shake out? How does the phrase, **“Yet once more,”** indicates the removal of things that are shaken? What are those things that are shaken in heaven and on earth?