Joel 2:1-3

Blow the trumpet in Zion! Sound the alarm on my holy mountain! Let all who live in the land tremble for the day of the Lord is coming—it's definitely near! It's a gloomy day of darkness, a day of thick clouds and heavy shadows. Like the dawn spreading over the mountains, an army appears, so large and powerful that there has never ever been anything like it before, nor will there ever be anything like it again. Fire blazes in front of them, behind them flames are burning. In front of them the land looks like the Garden of Eden, behind them is a desert of total desolation: not a single survivor remains.