Joel 2:1-2

Blow the horn in Zion; sound the alarm on My holy mountain! Let all the residents of the land tremble, for the Day of the LORD is coming; in fact, it is near — a day of darkness and gloom, a day of clouds and dense overcast, like the dawn spreading over the mountains; a great and strong people appears, such as never existed in ages past and never will again in all the generations to come.