Leviticus 26:36-37

36“As for those who remain, I will bring weakness into their hearts in the lands of their enemies, so that the sound of a driven leaf will put them to flight, and they will flee as one flees from the sword and fall, even when no one is pursuing.

37They will stumble over one another, as if before the sword, when no one pursues, and you will have no strength to stand before your enemies.