'To open,' as in Revelation 9, signifies communication and conjunction.

(Odkazy: Apocalypse Explained 537)

It is common in the Bible for people to "rise up," and it would be easy to pass over the phrase as simply describing a physical action. But in fact it represents an elevation in spiritual state, moving to a more internal frame of mind closer to the Lord. Often it has to do with understanding a new or important idea; we "rise up" to a state of greater perception and enlightenment. Obviously context is crucial to the exact meaning of the phrase in a given passage -- it matters greatly who it is that is rising up, and why.