Telling Phrase - Run Like the Devils Chasing You

This phrase exclaims a sense of urgency, a need to hurry up. If the devil were chasing you, you would run with a speed and intensity that is second to none. So if someone says for you to run like the devil is chasing you they are telling you that it is imperative that you get away from that situation as soon as possible. That you do not want to be anywhere near that situation.