Positive Mitzvah 104: Impurity of a "Zav"
Leviticus 15:2 "When any man has a running discharge of his flesh..."

Zav is a state of impurity that may befall a man.

People are mirrors for each other. If you see the faults of another and they don't leave you alone, it is truly your own faults you see. This is G-d's great kindness to us, for without this device we would never be able to determine our true faults.

From: Bringing Heaven Down to Earth by Tzvi Freeman - tzvif@aol.com