Joel 2:1-2

Blow a trumpet in Zion; sound an alarm on my holy mountain! Let all the inhabitants of the land tremble, for the day of the LORD is coming; it is near, a day of darkness and gloom, a day of clouds and thick darkness! Like blackness there is spread upon the mountains a great and powerful people; their like has never been before, nor will be again after them through the years of all generations.