The devastating consequences of Judah’s invasion by her enemies:The blowing of the trumpet, or shofar, an instrument made from a ram’s horn, normally signifies a call of strength or victory. In addition, the priests sound the trumpet to mark the beginning of sacred festivals (Lev. 25:9; Ps. 81:3), to gather the community in anticipation of a theophany (an appearance by God; Exod. 19:16–19; 20:18; Zech. 9:14), or at the inauguration of a new king (2 Sam. 15:10; 1 Kings 1:34, 39; 2 Kings 9:13). The command to sound the trumpet here serves as a warning to the people of an approaching danger for which they should prepare (cf. Jer. 4:5, 19–21; 6:17; Isa. 18:3; Ezek. 33:3–6; Hos. 8:1). Joel announces the im…