Joel 2:1-2

Blow the ram’s horn in Zion, sound the alarm on My holy mountain! All the inhabitants of the earth will tremble, because the day of the LORD has come, because it is near— a day of darkness and gloom, a day of clouds and thick darkness. Like blackness spreading over the mountain, a great and mighty army comes, such as was never before, and will never be again, even through the years of all generations.