Vayeira 5772

As Avraham negotiates with Hashem over Sodom and Gomorrah, Hashem promises that he will not destroy the cities if He finds there a certain amount of righteous people. The Ramban points out that Hashem doesn't tell Avraham that such a number doesn't exist in the cities; this is because they were still being judged in the Heavenly court. This shows us Hashem's mercy and wanting for us to do teshuvah. Even such evil people like the citizens of Sodom were given the opportunity to do teshuvah down to their last day.