“These are the offspring of Noah” – that is what is written: “The fruit of the righteous is a tree of life” (Proverbs 11:30). What are the fruits of the righteous? They are mitzvot and good deeds.6And this is why it states, “These are the offspring of Noah; Noah was a righteous man.” “And he who gathers souls is wise” (Proverbs 11:30) – as, [in his wisdom,] he fed and sustained7The animals that he had gathered. all twelve months in the ark. [Yet] after all this praise, “behold, retribution is made to the righteous on the earth” (Proverbs 11:31) – when he came to exit [the ark], retribution was exacted from him.
This is an astonishing statement! It is as Rav Huna said in the name of Rabbi Eliezer son of Rabbi Yosei HaGelili: As Noah was emerging from the ark, a lion bit him and maimed him. He was thus rendered unfit to sacrifice, and his son Shem sacrificed in his stead. [The verse continues with] an a fortiori conclusion: “all the more so, the wicked and the sinner” (Proverbs 11:31) – this is the generation of the Flood.