Revelation 4:1

After these things I saw, and behold, a door was opened in the heaven: and the first voice I heard was as of a trumpet speaking with me; saying; Come up hither, and I will show thee the things which it behooves to come to pass after these.

Revelation 1:10

I was in the Spirit on the Lord's day, and I heard behind me a great voice, as of a trumpet

Revelation 1:19

Therefore write the things which you have seen, and the things which are, and the things which are about to take place after these;

Revelation 11:12

And they heard a great voice out of the heaven saying to them, Come up hither; and they ascended up into the heaven in a cloud; and their enemies saw them.

Revelation 22:6

And he said to me, These words are faithful and true: and the Lord God of the spirits of the prophets has sent his angel to show to his servants the things which it behooves quickly to come to pass.

Matthew 3:16

And Jesus having been baptized, came up straightway from the water; and behold, the heavens were opened and He saw the Spirit of God, descending like a dove, coming on Him.

Mark 1:10

And coming up straightway from the water, He saw the heavens open and the Spirit like a dove descending on Him.

Luke 3:21

And it came to pass while all the people were being baptized, and Jesus having been baptized, and praying, the heaven was opened,

Acts 7:56

and said, Behold, I see the heavens opened, and the Son of man standing on the right hand of God.

Acts 10:11

and he saw the heaven open, and a certain vessel like a great sheet came down, and resting upon the earth with four rope ends:

Revelation 16:17

And the seventh poured out his bowl upon the air; and a great voice came out of the temple from the throne, saying, It is done.

John 16:13

But when He, the Spirit of truth, may come, He will guide you in all truth: for He will not speak from Himself; but so many things as He hears, He will speak: and will proclaim to you the things which are coming.

Revelation 1:1-3

The Revelation of Jesus Christ, which God gave to him, to show unto his servants the thing which it behooves speedily to come to pass; and he signified having sent by his angel to his servant John;

Treasury of Scripture Knowledge

Summary

After 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.

Bible References

A door

Matthew 3:16
And Jesus having been baptized, came up straightway from the water; and behold, the heavens were opened and He saw the Spirit of God, descending like a dove, coming on Him.
Mark 1:10
And coming up straightway from the water, He saw the heavens open and the Spirit like a dove descending on Him.
Luke 3:21
And it came to pass while all the people were being baptized, and Jesus having been baptized, and praying, the heaven was opened,
Acts 7:56
and said, Behold, I see the heavens opened, and the Son of man standing on the right hand of God.
Acts 10:11
and he saw the heaven open, and a certain vessel like a great sheet came down, and resting upon the earth with four rope ends:

The first

Revelation 1:10
I was in the Spirit on the Lord's day, and I heard behind me a great voice, as of a trumpet
Revelation 16:17
And the seventh poured out his bowl upon the air; and a great voice came out of the temple from the throne, saying, It is done.

And i

Revelation 1:19
Therefore write the things which you have seen, and the things which are, and the things which are about to take place after these;
Revelation 22:6
And he said to me, These words are faithful and true: and the Lord God of the spirits of the prophets has sent his angel to show to his servants the things which it behooves quickly to come to pass.
John 16:13
But when He, the Spirit of truth, may come, He will guide you in all truth: for He will not speak from Himself; but so many things as He hears, He will speak: and will proclaim to you the things which are coming.