55. And I heard behind me a great voice, as of a trumpet, signifies manifest perception of Divine truth about to be revealed from heaven. This is evident from the signification of "hearing," as being to perceive and obey (See Arcana Coelestia 2542, 3869, 4653, 5017, 7216, 8361, 8990, 9311, 9397); and from the signification of "behind me," as being manifestly (of which hereafter); and from the signification of "voice," when heard out of heaven, as being Divine truth (See Arcana Coelestia 219-220, 3563, 6971, 8813, 8914); and from the signification of a "trumpet," as being truth to be revealed out of heaven (of which hereafter). "Behind me" signifies manifestly, because the things that flow in from heaven into man's affection flow in into the occipital region, and come thus into his manifest perception; for whatever enters into affection is manifestly perceived, for the whole life of perception is from affection; but whatever flows out of heaven immediately into the thought flows into the region above the forehead. (Concerning this influx, see in the work on Heaven and Hell 251.) From this it is clear what is signified by John's having heard "behind him," and by his afterwards "having turned to see the voice which spoke with him." A "trumpet" or "horn" signifies Divine truth about to be revealed out of heaven, because sometimes Divine truth is heard in this way when it flows down from the Lord through the heavens with man; for it is increased in coming down; and it thus flows in. But it is thus heard only in the beginning with those through whom Divine truth is to be revealed in the ultimate sense, which is representative of interior things. But afterwards it is heard as a human voice. From this it is evident why "the voice of a trumpet" or "horn" signifies Divine truth about to be revealed out of heaven.

[2] He who is aware that "trumpet" or "horn," signifies Divine truth out of heaven can understand many passages in the Word where these are mentioned. As in Matthew:

He shall send forth His angel, with a great sound of a trumpet, and they shall gather together the elect from the four winds (Matthew 24:31).

In Isaiah:

All ye inhabitants of the world, and ye dwellers on the earth, when the sign of the mountains shall be lifted up, see ye; and when the trumpet is blown, hear ye (Isaiah 18:3).

In Jeremiah:

Proclaim with the trumpet in the land. Set up a standard towards Zion. How long shall I see the standard, and hear the sound of the trumpet? For my people are foolish, they are sottish sons, and they have no understanding (Jeremiah 4:5-6, 21-22).

In the same:

I set watchmen over you, saying, Hearken to the sound of the trumpet. But they said, We will not hearken. Therefore hear, ye nations (Jeremiah 6:17-18).

In Ezekiel:

He heard the sound of the trumpet, and took not warning; his blood shall be upon him; whereas if he had taken warning he should have delivered his soul (Ezekiel 33:5).

In Hosea:

[Set] the trumpet to thy mouth, because they have transgressed My covenant, and trespassed against My law (Hosea 8:1).

In Zechariah:

The Lord Jehovih shall blow the trumpet, and shall go with the whirlwinds of the south (Zechariah 9:14).

In David:

God is gone up with a shout, and Jehovah with the sound of a trumpet (Psalms 47:5).

And also in Revelation (chap. Revelation 4:1; 8:2, 7-8, 13; 9:1, 13, 14; 10:7; 18:22). Because a "trumpet" signified Divine truth, therefore when Divine truth was first about to be revealed before the people of Israel:

Sounds of a trumpet were heard from Mount Sinai (Exodus 19:16).

For this reason sounding the trumpet became representative with them:

When they were to assemble, and when they went forward, and also in their solemnities, at the beginnings of months, at burnt-offerings and eucharistic sacrifices (Numbers 10:1-10).

They also sounded trumpets when they went forth to battle against the Midianites (Numbers 31:6).

And when they took the city of Jericho (Joshua 6:4-20);

for wars and battles signified spiritual combats, which are combats of truth against falsity, and of falsity against truth.