On the fast day of Tzom Gedalya, we mourn the death of Gedalya ben Achikam. We learn a halacha (law) of Shemiras Halashon from the story of the death of Gedalyah. Although one may not accept and believe lashon hara, one is supposed to take precautions based on what he has heard. We can apply this idea to our teshuva during this season. Although we believe in our core goodness, we must worry about what we have done wrong and take proper action. Additionally, we learn the importance of judging an action based on its outcomes, not merely its perceived goodness or evil at the outset.