After (1) this I looked, and, behold, a door [was] opened in heaven: and the first voice which I heard [was] as it were of a trumpet talking with me; which said, Come up hither, and I will shew thee things which must be hereafter.
(1) Hereafter follows the second part of this book, altogether prophetical foretelling those things which were to come, as was said in (Revelation 1:19). This is divided into two histories: one common to the whole world, till Chapter 9 and another unique to the Church of God, till Chapter 22. These histories are said to be described in several books (Revelation 5:1; Revelation 10:2). Now this verse is a passage from the former part to this second: where it is said, that heaven was opened, that is, that heavenly things were unlocked and that a trumpet sounded in heaven, to stir up the apostle, and call him to the understanding of things to come. The first history has two parts: one the causes of things done and of this whole revelation in this next chapter, another of the acts done in the next four Chapter s. The principal causes according to the economy or dispensation of it, are two: One the beginning, which none can approach, that is, God the Father, of whom is spoken in this chapter. The other, the Son, who is the secondary cause, easy to be approached, in that he is God and man in one person; (Revelation 5:5-9).