Joel 2:2-3

2It is a day of darkness and gloom, a day of thick clouds and deep blackness. Suddenly, like dawn spreading across the mountains, a great and mighty army appears. Nothing like it has been seen before or will ever be seen again.

3Fire burns in front of them, and flames follow after them. Ahead of them the land lies as beautiful as the Garden of Eden. Behind them is nothing but desolation; not one thing escapes.