Superstition has it that, at all times, a devil waits over your left shoulder, and also that spilling salt is bad luck (perhaps because it used to be rare and precious). Hence, you can mitigate your bad luck by throwing salt into the eyes of the devil. There’s also a belief that your guardian angel (who can be found over your right shoulder) spills salt to warn you of evil nearby. Either you throw the salt to hurt the devil or, as salt was valuable, as an offering to placate him.
are you religious ????