Revelation 1:10-11; As of a Trumpet
Revelation 1:10-11 I was in the Spirit on the Lord’s day, and heard behind me a great voice, as of a trumpet, Saying, I am Alpha and Omega, the first and the last:and, What thou seest, write in a book, and send it unto the seven churches which are in Asia; unto Ephesus, and unto Smyrna, and unto Pergamos, and unto Thyatira, and unto Sardis, and unto Philadelphia, and unto Laodicea.
In Lev 23:23-25 the first day (new moon) of the seventh month is set apart as a solemn rest, “a memorial of blowing of trumpets” (the Hebrew leaves “of trumpets” to be understood), signalized further by “a holy convocation,” abstinence from work, and the presentation of “an offering made by fire.”
Horns are emblems of power, dominion, glory, and fierceness, as they are the chief means of attack and defence with the animals endowed with them (Da 8:5,9; 1Sa 2:1; 16:1,13; 1Ki 1:39; 22:11; Jos 6:4-5; Ps 75:5,10; 132:17; Lu 1:69, etc.). The expression “horn of salvation,” applied to Christ, means a salvation of strength, or a strong Saviour (Lu 1:69). To have the horn “exalted” denotes prosperity and triumph (Ps 89:17,24). To “lift up” the horn is to act proudly (Zec 1:21). [Easton Bible Dictionary]