Joel 2:1

“Blow ye the trumpet in Zion, and sound an alarm in my holy mountain, etc.] This is spoken to the priests, whose business it was to blow the trumpets for calling solemn assemblies to meet in Zion, the temple built there, called from thence the holy mountain of God. Here the trumpet is ordered to be blown with a broken quivering voice, a tarantantara, to give notice of approaching danger by the locusts, or those enemies signified by them, and to prepare for it, and return to God by repentance; let all the inhabitants of the land tremble; at the judgments of God coming upon them, and the alarm of them: for the day of the Lord cometh, for [it is] nigh at hand; the time fixed by him to punish a…”

“THE COMING JUDGMENT A MOTIVE TO REPENTANCE. PROMISE OF BLESSINGS IN THE LAST DAYS. (Joel 2:1-32) A more terrific judgment than that of the locusts is foretold, under imagery drawn from that of the calamity then engrossing the afflicted nation. He therefore exhorts to repentance, assuring the Jews of Jehovah's pity if they would repent. Promise of the Holy Spirit in the last days under Messiah, and the deliverance of all believers in Him. Blow . . . trumpet--to sound an alarm of coming war (Num 10:1-10; Hos 5:8; Amo 3:6); the office of the priests. Joe 1:15 is an anticipation of the fuller prophecy in this chapter.”

“Blow ye the trumpet - The trumpet was accustomed to sound in Zion, only for religious uses; to call together the congregations for holy meetings, to usher in the beginnings of their months and their solemn days with festival gladness. Now in Zion itself, the stronghold of the kingdom, the Holy City, the place which God chose to put His Name there, which He had promised to establish, the trumpet was to be used, only for sounds of alarm and fear. Alarm could not penetrate there, without having pervaded the whole land. With it, the whole human hope of Judah was gone. Sound an alarm in My holy mountain - He repeats the warning in varied expressions, in order the more to impress people’s hearts…”

“Blow ye - The prophet continues his exhortation to the priests, who were appointed to summon the solemn assemblies. Joel 2:2”

“2:1-11 Some regard this section as a second account of the locust plague described in ch 1, but in ch 1, the plague is in the past, whereas in this section, the verb tenses seem to depict it as a future event. Thus, others see it as a warning of yet another locust plague. Still other commentators have understood this passage as an apocalyptic description of the coming day of the Lord, using the language of a locust plague to describe an invading human army. 2:1 When an ancient city was attacked, the watchmen on the city wall would raise the alarm by blowing the trumpet, a ram’s horn instrument called a shofar (see also 2:15), to call all the defenders to repel the enemy.”

“Blow: Joe 2:15; Num 10:3, Num 10:8; Jer 4:5; Hos 8:1 trumpet: or, cornet, Ch1 15:28; Hos 5:8 and sound: Num 10:5-7, Num 10:9; Eze 33:3, Eze 33:6; Amo 3:6; Zep 1:16 in my: Joe 3:17; Psa 87:1; Dan 9:16, Dan 9:20; Zep 3:11; Zac 8:3 let: Ezr 9:3, Ezr 9:4; Psa 119:120; Isa 66:2, Isa 66:5; Jer 5:22, Jer 16:7, Jer 16:10; Dan 6:26; Phi 2:12 for the: Joe 1:15; Isa 2:12; Eze 7:5-7, Eze 7:10, Eze 7:12, Eze 12:23; Amo 8:2; Oba 1:15; Mal 4:1; Th1 5:2; Jam 5:8; Pe1 4:7 Joel 2:2”

“By blowing the far-sounding horn, the priests are to make known to the people the coming of the judgment, and to gather them together in the temple to pray. Joe 2:1. "Blow ye the trumpet upon Zion, and cause it to sound upon my holy mountain! All the inhabitants of the land shall tremble; for the day of Jehovah cometh, for it is near." That this summons is addressed to the priests, is evident from Joe 2:15, compared with Joe 2:14. On tiq‛ū shōphâr and hârı̄‛ū, see at Hos 5:8. "Upon Zion," i.e., from the top of the temple mountain. Zion is called the holy mountain, as in Psa 2:6, because the Lord was there enthroned in His sanctuary, on the summit of Moriah, which He claimed as His own.…”