The Torah states that Noach went into the Teivah (ark) “MiPnei Mei HaMabul,” “due to the waters of the flood” (Bereishis 7:7). Rashi comments on this Posuk that “Af Noach MiKetanei Amanah Hayah, Maamin VeEino Maamin SheYavo HaMabul,” “Noach, too, was one of those of little faith; he believed, but didn’t believe fully that the flood would actually come.” Therefore, Noach did not enter the Teivah until he saw with his own eyes that the waters of the flood had started to fall. Rashi’s explanation raises a very difficult problem: How could Noach, who was the biggest Tzaddik of his generation and has been compared to Avraham (though not as great as Avraham), have even the smallest doubt that the words of Hashem would be fulfilled?
Rav Yitzchak of Vorki relates interpretation of Rashi. Of course Rashi cannot assert that Noach had faulty faith! Rashi’s observation goes as follows: “Af Noach, MiKetanei Amanah Hayah Maamin,” “Even Noach believed in those of diminished faith,” and alleged that they would repent before the flood came. Therefore, “VeEino Maamin SheYavo HaMabul,” “(Noach) did not believe that the flood would come,” since if people repented, Hashem would have no basis for destroying the rest of mankind. However, this substantial atonement never happened, and Hashem was forced to cleanse the world through the flood.