In the Bible, trumpet blasts announced the coming of the king (1 Kings 1:34), a sacred event (Leviticus 25:9), a theophany (Exodus 20:18; Hebrews 12:19) a call to war (Judges 6:34; Judges 7:20; Isaiah 18:3) or the day of the Lord (Isaiah 27:13; Joel 2:1; Zechariah 9:14).
31 And he will send out his angels with a loud trumpet call, and they will gather his elect from the four winds, from one end of heaven to the other.