"And it came to pass on the third day, in the morning, that there were thunderings and lightnings, and a thick cloud on the mountain; and the sound of the trumpet was very loud, so that all the people who were in the camp trembled.  And Moses brought the people out of the camp to meet with God, and they stood at the foot of the mountain.  Now Mount Sinai was completely in smoke, because the Lord descended upon it in fire.  Its smoke ascended like the smoke of a furnace, and the whole mountain quaked greatly.  And when the blast of the trumpet sounded loud and became louder and louder, Moses spoke, and God answered him by voice."  (Exo. 19:16-19 NKJV)

 

 

      O my soul, my soul!
      I am pained in my very heart!
      My heart makes a noise in me;
      I cannot hold my peace,
      Because you have heard, O my soul,
      The sound of the trumpet,
      The alarm of war.

      (Jer. 4:19 NKJV)

 

      Also, I set watchmen over you, saying,
      ‘Listen to the sound of the trumpet!’
      But they said, ‘We will not listen.’
      (Jer. 6:17 NKJV)

 

      Blow the trumpet in Zion,
      And sound an alarm in My holy mountain!
      Let all the inhabitants of the land tremble;
      For the day of the LORD is coming,
      For it is at hand  (Joel 2:1 NKJV)

 

Again the word of the LORD came to me, saying, “Son of man, speak to the children of your people, and say to them: ‘When I bring the sword upon a land, and the people of the land take a man from their territory and make him their watchman, when he sees the sword coming upon the land, if he blows the trumpet and warns the people, then whoever hears the sound of the trumpet and does not take warning, if the sword comes and takes him away, his blood shall be on his own head. He heard the sound of the trumpet, but did not take warning; his blood shall be upon himself. But he who takes warning will save his life. But if the watchman sees the sword coming and does not blow the trumpet, and the people are not warned, and the sword comes and takes any person from among them, he is taken away in his iniquity; but his blood I will require at the watchman’s hand.’
“So you, son of man: I have made you a watchman for the house of Israel; therefore you shall hear a word from My mouth and warn them for Me. When I say to the wicked, ‘O wicked man, you shall surely die!’ and you do not speak to warn the wicked from his way, that wicked man shall die in his iniquity; but his blood I will require at your hand. Nevertheless if you warn the wicked to turn from his way, and he does not turn from his way, he shall die in his iniquity; but you have delivered your soul. 
“Therefore you, O son of man, say to the house of Israel: ‘Thus you say, “If our transgressions and our sins lie upon us, and we pine away in them, how can we then live?”’  Say to them: ‘As I live,’ says the Lord GOD, ‘I have no pleasure in the death of the wicked, but that the wicked turn from his way and live. Turn, turn from your evil ways! For why should you die, O house of Israel?’

(Ezek. 33:1-11 NKJV)

 

Behold, I tell you a mystery: We shall not all sleep, but we shall all be changed— in a moment, in the twinkling of an eye, at the last trumpet. For the trumpet will sound, and the dead will be raised incorruptible, and we shall be changed. (I Cor. 15:51-52 NKJV)

 

For the Lord Himself will descend from heaven with a shout, with the voice of an archangel, and with the trumpet of God. And the dead in Christ will rise first. (I Thes. 4:16 NKJV)

 

Then the seventh angel sounded: And there were loud voices in heaven, saying, “The kingdoms of this world have become the kingdoms of our Lord and of His Christ, and He shall reign forever and ever!” (Rev. 11:15 NKJV)

 

 

      So it shall be in that day:
      The great trumpet will be blown;
      They will come, who are about to perish in the land of Assyria,
      And they who are outcasts in the land of Egypt,
      And shall worship the LORD in the holy mount at Jerusalem.
      (Isa. 27:13 NKJV)