Joel 2:1-2

Blow the trumpet in Zion [warning of impending judgment], Sound an alarm on My holy mountain [Zion]! Let all the inhabitants of the land tremble and shudder in fear, For the [judgment] day of the LORD is coming; It is close at hand, [Ezek 7:2-4; Amos 5:16-20] A day of darkness and gloom, A day of clouds and of thick [dark] mist, Like the dawn spread over the mountains; There is a [pagan, hostile] people numerous and mighty, The like of which has never been before Nor will be again afterward Even for years of many generations.