Adam Clarke on Revelation 11:19

The temple of God was opened in heaven - The true worship of God was established and performed in the Christian Church; this is the true temple, that at Jerusalem being destroyed.

And there were lightnings, and voices, and thunderings, and an earthquake, and great hail - These great commotions were intended to introduce the following vision; for the 12th chapter is properly a continuation of the 11th, and should be read in strict connection with it.

I Now come to a part of this book that is deemed of the greatest importance by the Protestant Church, but is peculiarly difficult and obscure. I have often acknowledged my own incapacity to illustrate these prophecies. I might have availed myself of the labors of others, but I know not who is right; or whether any of the writers on this book have hit the sense is more than I can assert, and more than I think. The illustration of the 12th, 13th, and 17th chapters, which I have referred to in the preface, drawn up and displayed with great industry and learning, I shall insert in its place, as by far the most probable I have yet seen; but I leave the learned author responsible for his own particular views of the subject.