to sound a trumpet: to blow the signal blast that summons, warns, or announces that something is about to happen.
In the Bible a trumpet is a signalling device, not part of an orchestra. One blast could muster an army, warn a walled city, break off a battle, or open a festival day. This verb names that act and nothing more: the horn goes to the lips and the blast goes out. The instrument itself is a separate word (σάλπιγξ), and the man whose trade was blowing it is a third (σαλπιστής).
Ten of the twelve New Testament uses stand in Revelation, where seven angels blow in turn. Each blast is followed at once by a stroke of ruin on the earth, so the sound is never decoration. It is authorization: the signal has been given, and the next act begins. John counts the blasts the way an army would, and the last two are announced ahead of time so the reader hears them coming.
The two remaining uses pull in opposite directions from that same act. Paul leaves the player out of sight and simply says the trumpet will sound, and at that sound the dead are raised (1 Corinthians 15:52). Greek could use the verb this way, with no one named as the subject, much as we say "the bugle sounded" without asking who held it. Jesus uses it of a man making certain everyone notices his own generosity (Matthew 6:2), which lands very close to the English expression about blowing your own trumpet.
Nuances
Whether Matthew 6:2 reports an actual practice of sounding trumpets when alms were given, or uses the trumpet as a figure of speech for advertising one's own generosity.
- majorityThe trumpet is figurative, or deliberately exaggerated. No source outside this verse attests trumpet blasts at the giving of alms, so the picture caricatures the ostentatious giver rather than describing synagogue procedure.; W. D. Davies and Dale C. Allison, The Gospel According to Saint Matthew (ICC), vol. 1 (Edinburgh, 1988), on Matthew 6:2; Hans Dieter Betz, The Sermon on the Mount (Hermeneia; Minneapolis, 1995), on Matthew 6:2
- minorityThe trumpet is literal. Trumpets were sounded in the synagogue on public fast days, occasions on which collections for the poor were taken, and the verse assumes that setting.; Hermann L. Strack and Paul Billerbeck, Kommentar zum Neuen Testament aus Talmud und Midrasch, vol. 1 (Munich, 1922), on Matthew 6:2