Shiva and the Flood

We are told that the flood began on the seventeenth of Cheshvan, after a seven day waiting period. Rashi tells us that these seven days represent a mourning period for מתושלח, who was considered a righteous man. This is also seen as אסמכתא, a rabbinic law learned from the narrative of the text of the Torah. This is our first introduction to the concept of sitting Shiva. The קול התורה of Rabbi Munk, expands on this idea. He writes that Shiva is not only a time of mourning, but it is also a time for reflection and introspection. It is an opportunity for us to ponder what life is all about, as we grieve for a loved one. This was meant to shake up the generation of the flood, as a last ditch effort to get them to save themselves and mend their ways.