"These are the generations" (Genesis 6:9). In every place where it says "these," it disqualifies the earlier ones; "and these" adds to the earlier ones. Here, where it says "these," what did it disqualify? It disqualified the flood generation. "These are the generations" — this is what Scripture says, "He is swift upon the face of the waters" (Job 24:18) — a decree was decreed that they should perish in the water. "Their portion is cursed in the earth" (Job 24:18) — He who exacted punishment from the flood generation. Why all this? "He turns not by the way of the vineyards" (Job 24:18) — their intent was only to plant vineyards; but Noah's intent was only to be fruitful and to multiply in the world and to raise up sons.
These Are the Generations of Noah and the Vineyard of the Flood
Yalkut Shimoni on Torah 47:5
(בראשית ו ט) אֵלֶּה תּוֹלְדֹת. בְּכָל מָקוֹם שֶׁנֶּאֱמַר אֵלֶּה פָּסַל אֶת הָרִאשׁוֹנִים, וְאֵלֶּה מוֹסִיף עַל הָרִאשׁוֹנִים, כָּאן שֶׁנֶּאֱמַר אֵלֶּה מַה פָּסַל פָּסַל לְדוֹר הַמַּבּוּל. אֵלֶּה תּוֹלְדֹת. זֶה שֶׁאָמַר הַכָּתוּב "קַל הוּא עַל פְּנֵי מַיִם", גְּזֵרָה נִגְזְרָה שֶׁיֹּאבְדוּ בַּמַּיִם, (שם) "תְּקֻלַּל חֶלְקָתָם בָּאָרֶץ" מִי שֶׁפָּרַע מִדּוֹר הַמַּבּוּל, כָּל כָּךְ לָמָּה "לֹא יִפְנֶה דֶּרֶךְ כְּרָמִים" לֹא הָיְתָה כַּוָּנָתָן אֶלָּא לְמַטָּעַת כְּרָמִים אֲבָל נֹחַ לֹא הָיְתָה כַּוָּנָתוֹ אֶלָּא לִפְרוֹת וּלְהַרְבּוֹת בָּעוֹלָם וּלְהַעֲמִיד בָּנִים.