Joel
Joel 2:1BSB·traditional attribution

Blow the ram’s horn in Zion; sound the alarm on My holy mountain! Let all who dwell in the land tremble, for the Day of the LORD is coming; indeed, it is near—

John Calvin Reformed @genevareformer

This chapter contains serious exhortations, mixed with threatening; but the Prophet threatens for the purpose of correcting the indifference of the people, whom we have seen to have been very tardy to consider God’s judgments. Now the reason why I wished to join together these eleven verses was, because the design of the Prophet in them is no other than to stir up by fear the minds of the people.

Matthew Henry Presbyterian @wholebiblehenry

Here we have God contending with his own professing people for their sins and executing upon them the judgment written in the law (Deu 28:42), The fruit of thy land shall the locust consume, which was one of those diseases of Egypt that God would bring upon them, Deu 28:60. I.

Commenting on Joel 2:1-11

John Gill Reformed Baptist @doctorgill

Blow ye the trumpet in Zion, and sound an alarm in my holy mountain,.... 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.