It's okay to disagree with me. What I cannot agree with the historical interpretation is that the fact there was a voice from the temple of God when the sixth trumpet sounded.
Have you ever understood the plain text? I challenge you if you can explain it biblically for me please.

Rev. 9:13 "The sixth angel sounded his trumpet, and I heard a voice coming from the four horns of the golden altar that is beforeGod."

Since we understand Revelation from rather different viewpoints, my explanation needs a little background information

Revelation is first and foremost the Revelation of Jesus Christ. Christ in the heavenly sanctuary dealing with the sin problem.

BASICS FROM THE EARTHLY PATTERN
I see revelation showing Christ's ministry through all THREE representatives of the earthly sanctuary.
1. The outer court with it?s altar of sacrifice and laver. This is where the sacrifice is slain.
2. The holy place, with it?s table of bread, altar of incense and its candlestick, where the priest ministers daily.
3. The Most Holy Place, with its ark of the covenant and mercy seat, where the Priest ministers on the day of Atonement.
These three steps have their reality in the heavenly ministry of the heavenly sanctuary.

OUTER COURT FULFILLED
Christ's all sufficient sacrifice took place on earth (represented by the outer court)
But that was just the beginning of the sanctuary work. Hebrews announces Christ entered the heavenly sanctuary, the holy places, as our High Priest.

CHRIST BEGINS HIS WORK AS HIGH PRIETS
I see Revelation 4 and 5 as the scene of Christ's ascension and acceptance as the only One Worthy "For you were slain, and have redeemed us to God by Your blood" (Rev,5:9)
Compare with Hebrews 5:5-6 "Christ did not exalt himself to be made a high priest, but was appointed by him who said to him,
?You are my Son, today I have begotten you?; as he says also in another place, ?You are a priest forever, after the order of Melchizedek.?
In the days of his flesh, Jesus offered up prayers and supplications, with loud cries and tears, to him who was able to save him from death, and he was heard because of his reverence. Although he was a son, he learned obedience through what he suffered. And being made perfect, he became the source of eternal salvation to all who obey him, being designated by God a high priest after the order of Melchizedek."

He was the only One Who was worthy to take the scroll, make intercession for the people, forgive their sins, and execute all the conditions of the covenant.
Revelation chapters four to five is the grand opening of the heavenly sanctuary work as the only One worthy to be High Priest having lived, died and risen again, is given the book of the covenant ."the roll of the history of God's providences, the prophetic history of nations and the church. Herein was contained the divine utterances, His authority, His commandments, His laws, the whole symbolic counsel of the Eternal, and the history of all ruling powers in the nations. In symbolic language was contained in that roll the influence of every nation, tongue, and people from the beginning of earth's history to its close".9MR 7.1

IT'S HOLY PLACE FURNITURE
Revelation reveals Christ's work in the Holy Place with its incense and candlesticks.
Revelation 4 what do we see, do we see the furniture of the holy place, or the most holy? It is the furniture of the holy place.

AND A VOICE IS HEARD!!! A door in heaven is open. (Rev. 4:1) And a voice like a trumpet said, "Come up here, I will show things which must take place. What door is this?
The word "door" "thura," in Revelation 4:1 appears many times in the Septuagint in direct reference to the door into the sanctuary itself. Leviticus 3:1 tells us the sacrifice is killed at the "thura" of the tabernacle.

And here in heaven we see the Lamb that has already been slain! The sacrifice was offered, and now the door into the heavenly sanctuary is open. This is the door into the holy place.

GOD'S THRONE
Some contend that because God's throne is a central feature in these chapters, it must mean that Christ began His ministry immediately in the Most Holy Place, for, they say God's throne is only in the Most Holy Place. But the Bible does not confine it thus. Any place where God's throne is, is extremely Holy. However, look in the last chapters of Revelation, and you will see God's throne in the center of New Jerusalem where there is no temple. Look in the first chapters of Ezekiel and you will see God's throne on living wheels within wheels, accompanied by four beasts and angels, moving! God's throne is central! Look in Daniel 7 and see God's throne on wheels as well. Thrones being set up. God is very much involved and interested in our salvation as Christ is. God and Jesus are One! They work together. Why place human limitations on where God can be, and keep Him on a stationary throne, and then build a doctrine on such a limitation?

Besides we see in chapter 4 and 5, the furniture of the Holy Place not the Most Holy. We see seven lampstands and we see the twenty-four elders with golden bowls full of incense. This is part of the daily. It isn't until later in the book of Revelation that judgment is announced, and then we see the furniture from the Most Holy.

CHRIST'S INTERCEDING AT THE ALTAR
Revelation 8, we see Christ in the Holy Place by the altar of incense interceding for people, offering incense with the prayers of all the saints upon the golden altar.
This is Jesus work in the Holy Place for 1810 years of earth's history.
If you study the pattern, it isn't till the priest fills the censor with coals from the altar that He enters the Most Holy. While the scene tells us this will also happen at the end, the first part is obvious;y showing what Christ was doing in the Holy Place.

VOICES FROM HEAVEN
The first one was calling John to "come and see" in Rev. 4:1 Come and see the opening of the sanctuary.
The second one is in Rev. 5:2 " I saw a strong angel proclaiming with a loud voice, Who is worthy to open the book, and to loose the seals thereof?
And all the angel's and elders and living creatures respond with a loud voice "Worthy is the Lamb Who was slain..." The work in the sanctuary can begin, the Worthy One to be it's High Priest has been found and He will implement all the things written in the book of the covenant.
In chapter 18:4 we hear urgent voice from heaven calling God's people out of Babylon before it is too late.
And yes, there is also a voice when everything "is done"
So the voices have things to announce all through the Christian era! All through the time the sanctuary in heaven is dealing with the sin problems of earth.



So what does all this mean concerning the text under discussion?
Rev. 9:13-14 Then the sixth angel sounded: And I heard a voice from the four horns of the golden altar which is before God, saying to the sixth angel who had the trumpet. Release the four angels who are bound at the great river Euphrates."

What furniture do we see here? We see the altar of incense. Where is the altar of incense in the earthly example? In the holy place.
The fact that the sixth trumpet is initiated from the altar of incense shows that the prayers of God's people are still being mixed with incense by Jesus . Probation is open. Jesus is still at the altar of incense.

At the sounding of the sixth trumpet, 4 angels are released from their bondage at the Euphrates river by the 6th angel, Rev. 9:16 ?So the four angels, who had been prepared for the hour and day and month and year, were released to kill a third of mankind".
This voice is announcing that things in the world are about to get much worse. Evil angels that had been bound, restrained, are released. But it's not the end, there is still time to repent, there is still mercy being extended.
While evil is allowed to greatly intensify it's power, people need to remember the power of the four horns on the altar of incense.
Those four horns symbolized salvation's power, protection, refuge. {Ps.18:2, 1 Kings 1:50, Luke 1:69)
They are still part of the altar of incense, they have not been cut off.
As evil multiplies, the message is to flee to the altar of incense, grab firm hold on those four horns, repent, Christ offers salvation.

ANOTHER THOUGHT
Back in OT times, Israel fell into worshipping other gods, and even built altars with four horns to worship these gods.
Amos 3:14 When God punishes Israel for their transgression He will visit these false altars and cut off their horns.
The sixth trumpet angel in Rev. 9:20 reveals transgressions as worshipping demons as people clung to their idols of gold, silver, brass, stone.

There was no strength of salvation in those false alters. When trouble comes, serious trouble, the horns on those idol alters break off. They don't protect anyone, those who trust in them are prey to their enemies. Sadly the world doesn't recognize the uselessness of their idols, they don't repent and just continue to trust in counterfeits..
But there is a true altar of incense with four horns of salvation offered to anyone who would grab firm hold of those four horns, repent and accept Christ's salvation.

The concept of the voice from the midst of the four horns has a significant implication: the OT sanctuary background undergirds the understanding.

God gave Moses precise instructions for building a sanctuary in Exodus 25:9. "According to all that I shew thee, after the pattern of the tabernacle, and the pattern of all the instruments thereof, even so shall ye make it" (Ex. 25:9).

God begins to show the furniture of the Most Holy Place, then the articles of the Holy Place, which are the table of bread and the candlestick. Notice that an instruction to make a golden altar is not yet given in the respective order.

The intimation is that the high priest's work concludes when he applies the blood of an ox and goat upon the four horns of the golden altar on the way out from the Most Holy Place.

The instruction to make a golden altar comes after all the others of the curtains, the vail, the brazen altar, and the holy priest's garments, etc.

In Chapter 30 of Exodus, the precise instruction to make a golden altar and its placement is given at last, including Aaron's work of the day of atonement.

Ex. 30:10 "And Aaron shall make an atonement upon the horns of it once in a year with the blood of the sin offering of atonements: once in the year shall he make atonement upon it throughout your generations: it is most holy unto the LORD."

The profound significance of blood application upon the horn, which is upon the golden altar, is that the probation is closed, and no more mercy of God is available.

Therefore, when a voice comes out from the four horns of the altar suggests that God's mercy ended for the probation of humanity. The sixth trumpet is speaking about a future event: God's mercy has not finished yet.

Rev. 9:13 "The sixth angel sounded his trumpet, and I heard a voice coming from the four horns of the golden altar that is before God."

Probation is closed, no more mercy? Before the seventh trumpet sounds in which the door to the ark of the covenant is opened? And the message of the work of Christ in the Most Holy Place is given????

What about these quotes? Remember Revelation 11:19 is part of the SEVENTH Trumpet, and this was not just stated once, but several times over and over.

Looking at the text again.
1. There is no mention of blood, or Christ touching the four horns in Rev. 9:13. That interpretation is based on "maybe" "could be" ideas, not on the text itself.
There is nothing that hints probation is closed at that point. Repentance is mentioned twice showing that the action of the sixth trumpet angel in unleashing the restrained evil angels, was meant to shake up the people and bring them to repentance. It is highly regretted that it didn't bring them to repentance, but it COULD HAVE!

2. Order of the furniture mentioned in Moses writings?
Exodus 37, and 39, the order is different.

The purpose of the altar of incense makes it possible for forgiven people to approach God. Incense was offered every day, morning and evening. It represents Christ's merits that permit people to approach God.

A voice coming from the four horns in the temple is a call to come to God,. It's more akin to the message of the angel in Rev. 18, to come out, to accept Christ's merits, and turn to Him for salvation and protection. Trouble is coming, it's multiplying, please recognize your need, turn, repent, but they repented not but continued to trust in their idols.

3. Looking in the Old Testament for understanding:

The altar of incense in Jerusalem was God's altar representing the altar in heaven.

BUT

When Israel split away from Judea, other altars of incense were built, a main one in Bethel.
1 Kings 12, Jeroboam their king, set up these altars of incense after the pattern of the real one in Jerusalem,
and set them before golden calves and told the people, these are your gods.
12:30-32 And this thing became a sin:
he offered upon the altar which he had made in Bethel the fifteenth day of the eighth month, [even] in the month which he had devised of his own heart; and ordained a feast unto the children of Israel: and he offered upon the altar, and burnt incense.

The type here is taking the things of God, making counterfeits, and saying they are the true.

God sent a prophet to Jeroboam who was offering incense on the counterfeit altar:
1 Kings 13:3 And he gave a sign the same day, saying, This [is] the sign which the LORD hath spoken; Behold, the altar shall be rent, and the ashes that [are] upon it shall be poured out.

Amos the prophet speaks of these counterfeit altars of incense.
3:14 That in the day that I shall visit the transgressions of Israel upon him I will also visit the altars of Bethel: and the horns of that altar shall be cut off, and fall to the ground.


This fits Revelation 9:13 very well:

9:13 And the sixth angel sounded, and I heard a voice from the four horns of the golden altar which is before God, (the true altar of incense)
9:15 And the four angels were loosed, which were prepared for an hour, and a day, and a month, and a year, for to slay the third part of men. (Armies released against the counterfeit, as also previously released upon Israel, armies that come to slay them )
9:20 And the rest of the men which were not killed by these calamities yet repented not of the works of their hands, that they should not worship devils, and idols of gold, and silver, and brass, and stone, and of wood: (counterfeits used to pretend to be the real) which neither can see, nor hear, nor walk:
9:21 Neither repented they of their murders, nor of their sorceries, nor of their fornication, nor of their thefts.

The fact that they repented not, shows they COULD have repented. That was the hope that they would see the folly of looking to these counterfeits as the solution to their problems.

Sadly the world doesn't recognize the uselessness of their idols, they enjoy them, so they don't repent and just continue to trust in counterfeits for solutions, but they can't save or protect, just leads to misery and destruction.

The big problem --
The things of God have been taken over by a powerful religious/political identity and offered to the people as the truth, just like in the days of Jeroboam. Israel, had armies released against them. The counterfeit church had armies released to come against them, they had many serious warnings. It's all warnings -- the counterfeit will not win, turn to the true altar of salvation.

Dedication: I like your above post, makes me think. If I may, please let me share some on one of your points:

"1. There is no mention of blood, or Christ touching the four horns in Rev. 9:13. That interpretation is based on "maybe" "could be" ideas, not on the text itself.
There is nothing that hints probation is closed at that point. Repentance is mentioned twice showing that the action of the sixth trumpet angel in unleashing the restrained evil angels, was meant to shake up the people and bring them to repentance. It is highly regretted that it didn't bring them to repentance, but it COULD HAVE!"

I agree with this post. but there is something that I am not fully comfortable with; actually, I'm completely uncomfortable with; but yet the evidence seems to be there: With the 6th trumpet, instead of repenting people blame and curse God. Then comes the events in Revelation 11 where the message of the Bible grows; although rejected. But then there is the great earthquake where a tenth of the city was destroyed and 7,000 people were killed. Now, where have we seen 10% in the Bible before? (picture me tapping my forehead to remember with a tithe envelope) 10% is what belongs to God. This is a little harder, but what about the7,000? God told Elijah that there were 7,000 who did not bow to Baal. The 10% and 7,000 represent God's people. As these people who cursed God at the 6th trumpet see how God's people face martyrdom and mistreatment. As they see how God's people face persecution the Bible says that the survivors gave glory to God, leading to the 7th trumpet that says the kingdoms of this world is become the kingdom of our God and of his Christ, and He shall reign forever and ever.

This indicates a large repentance. I am uncomfortable about making this too big, but I wonder if this is the outpouring of the Holy Spirit and the latter rain?

Again, this comes from the understanding that the 7 trumpets are the little time of trouble prior to the close of probation; a time where believers will be martyred but their deaths will change lives. Then come the great time of trouble, the 7 last plagues, where probation has closed. No longer will believers die because their deaths cannot change hearts. Satan tries his worst to force people to curse God. Could this be that among the people who he was successful in getting to curse God in the 6th trumpet, but who was effected by the martyrdom of God's people (the 10% and 7,000) so that they turn to Christ and become a part of His kingdom, and He shall reign in their hearts forever and ever. Satan feels that since he could get them to curse God with the 6th trumpet, that he can easilly cause them to curse God again; but they stay faithful.

Thanks for clarifying. You probably agree more with Karen, than with me in the placements of the trumpets. Though she believes probation closes in the sixth trumpet, which I don't think is your view.
In my understanding six of the trumpets sounded in the past, and we are now in the Seventh Trumpet, the writer, John, giving us the endpoint of that trumpet, before giving events leading up to the conclusion.

I can understand your discomforted in the phrase they "repented not" for God has always had His faithful who have not "bowed the knee to Baal."
In my understanding the sixth trumpet announces that restraint on evil was loosened, four bound angels were loosed. God's protection withdrawn from a church both east and west,a church that was counterfeiting God's salvation and persecuting those who were holding on to truths. Vast armies of Moslems and others, attacked the unfaithful, counterfeiting, intolerant church. The Byzantine church lost it's center (Constantinople) and fled mainly north to Russia. The Roman church also suffered considerably. But these entities and their followers did not repent.

Revelation 11 depicts the rise of humanism/atheisms in the French Revolution. They tried to destroy the two witness (Old and New Testament).
But instead of destroying them, the bible gained never seen before popularity and distribution .

The numbers 10th and 7000 are interesting, but it's the tenth part of the city and it fell, Kind of, doesn't sound like they are representing God's true followers. Though maybe, when the Huguenots fled France, 10% of the population was gone. Though they fled much earlier. And the 7000 who were slain? During the French revolution a huge number of people died. These 7000 could Maybe be martyrs?

The whole message of the seven trumpets is about the close of probation, which the introduction's snapshot proves, not only the sixth trumpet. The trumpet sound is not a past event(s) because the seven angels prepared themselves to sound after Jesus cast down the fire of the golden altar, indicating the close of probation.

The prophecy book, Revelation, is given to all the believers of Jesus Christ. With that said, the account of EG White's quotes does not substantiate the biblical interpretation.

Rev. 8:5-6 "And the angel took the censer, and filled it with fire of the altar, and cast it into the earth: and there were voices, and thunderings, and lightnings, and an earthquake. And the seven angels which had the seven trumpets prepared themselves to sound."

I see, EGW's comments are not to be considered.
So if a person can come up with an interpretation that causes people to reject her writings, is that a good thing, even when an interpretation that fully supports her writings can be plainly shown?

Revelation gives the story of history in cyclic revelations.
So we see in chapters 1-12 the prophecies keep going over the same history from start to finish several times each time showing a different aspect of what's going on during this time.
Chapter 12 takes us even further back to the spiritual powers at the root of the conflict, and then announces the last war at the time of the end.
Chapters 13 to 19 describe the last war. The end time events
Chapters 20 -22 tell us what happens after Christ's second coming

Thus Revelation 8:2-5 Tells us what Christ is DOING in heaven during the same time period when the trumpets sound on earth.

First Christ is ministering in the holy place at the altar of incense
He will take the coals of the altar, put them in the golden censer to continue His work in the Most Holy.
---- that act was always done on the day atonement.
When He comes out, yes, He will cast down the censer showing it is done.
THEN the thunders and voices, lightning and earthquake, etc.

See it outlined in the chart below.

The first trumpet message has a clear connection to Rev. 7:1-3.

Rev. 7:1-3 "And after these things I saw four angels standing on the four corners of the earth, holding the four winds of the earth, that the wind should not blow on the earth, nor on the sea, nor on any tree.
And I saw another angel ascending from the east, having the seal of the living God: and he cried with a loud voice to the four angels, to whom it was given to hurt the earth and the sea,
Saying, Hurt not the earth, neither the sea, nor the trees, till we have sealed the servants of our God in their foreheads."

The first trumpet says that "...and the third part of trees was burnt up, and all green grass was burnt up." In other words, the command in Rev. 7:1-3 fulfilled in the reality of the first trumpet event.

In juxtaposing the passages, the command of Chap. 7 says, "do not hurt the sea, trees" upon the earth while the sealing work of God progresses. The other text of 1/3 trees and green grass burnt up indicates that God would have completed the sealing work as the trumpet's warning. The tree represents the world's leader (Dan. 4:22), and the green grass represents people(Isa. 40:6).

Conversely, the first trumpet says that God will destroy 1/3 of the trees and all green grass at the point when the sealing work is finished. Then, there is no more of the ministry of Intercessor in the heavenly sanctuary and no more mercy for the impenitence. Now, it is time for the final seven last plagues.

At the fulfillment of Rev. 7:1-3 the close of probation happens, and only those who receive the mark of the beast and worship the beast will have to face the seven last plagues.

Rev. 16:2 "And the first went, and poured out his vial upon the earth; and there fell a noisome and grievous sore upon the men which had the mark of the beast, and upon them which worshipped his image."

The description of the first plague lines up with the first trumpet's warning, which is hail and fire mixed with blood cast upon the earth and the earth dwellers burnt up(trees and all green grass burnt up). At the close of probation, the wicked alive would have all received the mark of the beast and worshiped his image.

The unity of the seven trumpets conveys the warning of the close of probation, and we can identify its fulfillment from the seven plagues.