Commentaire sur Joël 2:1

Sound a shophar—to announce to them that they should repent before the evil befalls them.

1. "Blow a shofar in Zion..." The prophet brings two separate topics here. The first begins with "blow a shofar in Zion" and the second begins with "blow a shofar and call a fast". And this is because they both deal with the destruction of the temples. The destruction of the first temple in the first section and the destruction of the second temple and it's redemption in the second section. And it says in this first section "blow a shofar in Zion. call out at My holy mountain" because it's specifically discussing the kingdom of Judah and therefore it specifies Jerusalem. Blow a shofar to publicize her destructions. And the "holy mountain" is about the Temple which is destroyed like it says (Tehillim 24:4) "who will ascend on the mountain of Gd and who will get up in His holy place" and there as well the "holy mountain" refers to the Temple. And regarding the land of Judah it says "all the inhabitants of the land will tremble' and the blowing of the shofar will let them know that the day of Gd is close, similarly to how the shofar is blowing to start the Yovel year and it lets the inhabitants know that it is a Gdly time for each man to return to his portion and to his family. And therefore the shofar is also blown at the time of Gd to go into exile and leave portions and leave families. And this is all to let us know that the day of Gd is coming. The explanation is it is coming close and it's like it is already here and happening. And this is related to the mourning of the priests in earlier psukim that we are told about the mourning before it actually happens as well. And this is all to let us know that also at the time of the trouble it is good to repent and return to Gd

the day of the Lord—which we mentioned above.