Mishneh Torah – Laws of Fasts
Mishneh Torah, Fasts 1:1-4
The Rambam opens his Laws of Fasts by establishing that it is a positive commandment to cry out and blow trumpets (חצוצרות) whenever trouble befalls the community. He explains that this is the fundamental meaning of prayer — recognizing that suffering comes from God and that one must turn to Him. The trumpet blowing is part of this act of awakening the heart in prayer.
מִצְוַת עֲשֵׂה מִן הַתּוֹרָה לִזְעֹק וּלְהָרִיעַ בַּחֲצוֹצְרוֹת עַל כָּל צָרָה שֶׁתָּבוֹא עַל הַצִּבּוּר. שֶׁנֶּאֱמַר (במדבר י ט) "עַל הַצַּר הַצֹּרֵר אֶתְכֶם וַהֲרֵעֹתֶם בַּחֲצֹצְרוֹת". כְּלוֹמַר כָּל דָּבָר שֶׁיָּצֵר לָכֶם כְּגוֹן בַּצֹּרֶת וְדֶבֶר וְאַרְבֶּה וְכַיּוֹצֵא בָּהֶן זַעֲקוּ עֲלֵיהֶן וְהָרִיעוּ: וְדָבָר זֶה מִדַּרְכֵי הַתְּשׁוּבָה הוּא. שֶׁבִּזְמַן שֶׁתָּבוֹא צָרָה וְיִזְעֲקוּ עָלֶיהָ וְיָרִיעוּ יֵדְעוּ הַכּל שֶׁבִּגְלַל מַעֲשֵׂיהֶם הָרָעִים הוּרַע לָהֶן כַּכָּתוּב (ירמיה ה כה) "עֲוֹנוֹתֵיכֶם הִטּוּ" וְגוֹ'. וְזֶה הוּא שֶׁיִּגְרֹם לָהֶם לְהָסִיר הַצָּרָה מֵעֲלֵיהֶם:
It is a positive Torah commandment to cry out and to sound trumpets in the event of any difficulty that arises which affects the community, as [Numbers 10:9] states: "[When you go out to war... against] an enemy who attacks you and you sound the trumpets...." [This commandment is not restricted to such a limited scope; rather] the intent is: Whenever you are distressed by difficulties - e.g., famine, plague, locusts, or the like - cry out [to God] because of them and sound the trumpets. This practice is one of the paths of repentance, for when a difficulty arises, and the people cry out [to God] and sound the trumpets, everyone will realize that [the difficulty] occurred because of their evil conduct, as [Jeremiah 5:25] states: "Your sins have turned away [the rains and the harvest climate]." This [realization] will cause the removal of this difficulty.