(1) ... Where is it shown that He mourned [before the flood]? Where it is stated (in Gen. 6:6), “Then the Lord regretted that He had made humanity on the earth, and He was grieving in his heart.” [The expression] “He was grieving” can only mean, He mourned. For so it says concerning David (in II Sam. 19:3), “And the victory [on that day] was turned into mourning for all the people because [on that day they heard it being said,] ‘The king was grieving over his son.’” So also Ezra said to Israel when they were weeping, each one for his brother and each one for his child (in Neh. 8:10), “Go, eat choice foods and drink sweet drinks…. Do not be grieving, for the joy of the Lord is your strength.” It is therefore stated (in Gen. 6:6), “and He was grieving in his heart.” At that time the Holy One, blessed be He, observed the seven days of mourning, before He brought the flood. Thus it is stated (in Gen. 7:10), “And it came to pass after seven days [that the waters of the flood came upon the earth].” And so Moses was saying to Aaron the priest and to his sons, “Just as the Holy One, blessed be He, mourned over His world before He brought the flood, so [you are to] observe the [required] mourning before it touches (i.e., harms) you.” So they observed [the mourning], but they did not know for what reason they were observing it.