Parashat Tazria speaks at length of the laws of the Sara’at skin disease that would descend upon a person as a punishment for Lashon Hara – speaking negatively about other people. A person who was determined to have been stricken with Sara’at was quarantined, and was required to live in solitude outside his city. The Torah writes that as the person made his way from his home to his place of solitary confinement, he would have to announce, "Tameh Tameh!" ("Impure! Impure!" –13:45). On the simple level of interpretation, this announcement was required in order to warn people to keep away from this individual. People were urged not to come near the person stricken with Sara’at so that they would not become Tameh (ritually impure).
The Sages, however, noted an additional reason for this announcement. The Mesora (person stricken with Sara’at) would inform everyone of his condition so that they would pray on his behalf. Essentially, he was saying, "Help me! I have Sara’at! Please pray to God that I will soon be healed!"
The obvious question arises, why doesn’t the Mesora pray for himself? Why must he implore others to pray for him?
The Hafetz Haim (Rav Yisrael Meir Kagan of Radin, 1839-1933) explained, quite simply, that the Mesora’s prayers cannot be accepted. Having contaminated his mouth through sins of speech, by speaking derisively about other people and indulging in gossip, he has lost the power of Tefila. The prayers that come from such a mouth are tainted and damaged; they cannot achieve the desired effect. For this reason, the Mesora has no choice but to ask others to pray on his behalf, until he corrected his sinful tendency and repented, thereby regaining his mouth’s purity which we need for our prayers to gain acceptance.
This is also why we begin the observance of Yom Kippur with the "Kol Nidreh" service, in which we formally annul any vows that we had taken. Before we spend Yom Kippur praying for forgiveness, we must first ensure that we are not guilty of sins involving speech. Otherwise, our prayers are futile. If our mouths bear the stain of forbidden speech, then our prayers are ineffective.
A gossiper not only hurts the people he speaks about; he hurts himself. We all have difficult problems and concerns, we all desperately need the Almighty’s help on so many levels. Nobody can afford to forfeit the power of prayer by contaminating his mouth. Let us ensure to keep our mouths free of sin, so that our prayers will have the desired effect and proceed directly to the heavens, where they will be lovingly and eagerly accepted by God.