Apocalypse Revealed #412
412. Then the fourth angel sounded. (8:12) This symbolizes an examination and disclosure of the state of the church in people for whom religion is faith alone, that they are caught up in the evils accompanying falsity and in the falsities accompanying evil.
That this is the symbolic meaning follows from what follows next, understood in the spiritual sense.
To sound a trumpet here means, symbolically, to examine and expose, as in nos. 398, 402, and 407, above.
Jeremiah 33:20-21
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Thus says Yahweh: If you can break my covenant of the day, and my covenant of the night, so that there shall not be day and night in their season;
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then may also my covenant be broken with David my servant, that he shall not have a son to reign on his throne; and with the Levites the priests, my ministers.