"We know that a trumpet is usually not so much heard as dreaded; it is not so much accustomed to bring pleasure as to inspire fear. A trumpet is necessary for sinners; it not only penetrates their ears but should strike their heart as well; it should not delight with its melody but chastise when it has been heard; it should encourage the bravehearted to righteousness, while it should turn the cowardly from their crimes" - Maximus of Turin
(Sermon 93.1, Ancient Christian Writers: The Works of the Fathers in Translation, Mawah, NJ: Paulist Press, 1946, 50:215.)
Isaiah 58 starts with a comparison of crying repentance to a blast from a trumpet ( shofar)
Isaiah 58:1It then moves into a detailed explanation of sins with the backdrop of the annual day of fasting, which is the Day of Atonement (Lev 16), a release from the bondage of sins at the time of the autumnal harvest, or ingathering (the Jubilee and Sabbatical years that prescribed a release from servitude and debt were aligned to start with the Day of Atonement). Isa 58:6 talks of loosing bands, undoing burdens, breaking yokes and letting the oppressed go free. It is often associated with Israel's failure to release their servants as required by law (e.g., Exodus 21:2). The harvest feasts such as the Day of Atonement and the Feats of Trumpets (as with most ritual acts and celebratory gatherings in ancient Israel) start with the blowing of the shofar:
1 Cry aloud, spare not, lift up thy voice like a trumpet, and shew thy people their transgression, and the house of Jacob their sins.
Leviticus 23:24Interestingly, the Hebrew for this verse does not even contain the word 'trumpet.' The Hebrew word teruah (translated in the KJV as “blowing of trumpets”) means literally to "raise a noise" and can be used for the sound of a voice that shouts or for the sound that issues from a trumpet. Not only is teruah the word behind the “trumpet blasts” here in Leviticus, it's also the word used when congregated Israel “shouts” on the arrival of the Ark (1 Sam 4:5) and when the sons of God “shout” for joy (Job 38:7). Because of this, when Isaiah juxtaposes the concept of crying aloud with lifting one's voice as a trumpet, the imagery is particularly effective. And the theme of lifting one's voice as a trumpet against sin in the context of deliverance from bondage is picked up elsewhere:
24 Speak unto the children of Israel, saying, In the seventh month, in the first day of the month, shall ye have a sabbath, a memorial of blowing of trumpets, an holy convocation.
Hosea 8:1You can see the same principles in action in Jer 4:5 and Ezek 33:6. And the theme is resurrected in the New Testament in the book of Revelation, where John is told to cry repentance to the seven churches in Asia. Set against a panoply of imagery associated with the autumnal harvest festival, John hears behind him "a great voice, as of a trumpet" (1:10; see also 4:1). The message is clear: "Remember therefore from whence thou art fallen, and repent, and do the first works; or else I will come unto thee quickly and will remove thy candlestick out of his place, except thou repent" (2:5). It's another example of the prophetic voice crying out like a trumpet to issue a call to repentance during a time associated with release from bondage and sin.
1 Set the trumpet to thy mouth . . . because they have transgressed my covenant, and trespassed against my law.
Enter Alma, who uses the exact metaphor in the same context:
Alma 29:1And this call to repentance is set within the context of deliverance from bondage:
1 . . . that I might go forth and speak with the trump of God, with
a voice to shake the earth, and cry repentance unto every people!
He finishes up with harvest/ingathering imagery:
11 Yea, and I also remember the captivity of my fathers; for I
surely do know that the Lord did deliver them from bondage . . .
12 Yea, I have always remembered the captivity of my fathers; and that same God who delivered them out of the hands of the Egyptians did deliver them out of bondage.
Alma 29:15I think I just might have to buy a trumpet and start our Family Home Evenings with a blast to repentance!
15 Behold, they have labored exceedingly, and have brought forth much fruit.
17 And now may God grant unto these, my brethren, that they may sit down in the kingdom of God; yea, and also all those who are the fruit of their labors that they may go no more out . . .