Rashi comments here that the righteous regard their good deeds as their progeny.
Rabbi Yaakov Yitzhak of Parshischa used to say: Every man says that he works and toils only for his children, so that they may grow up to become good Jews, well-versed in the Torah. But when the children are grown, they, as parents, continue to insist that they have no time to think about their own Torah study because they must attend to the training of their children.
The Torah points out that Noach regarded himself as a “child” in that sense of the word - “These are the progeny of Noach.” Noach was not content to devote all his time to the education of his children. He thought of his own personality, too, as a “child” who is in need of education and improvement. Thus, working to increase his own knowledge and to improve his own character, Noach became “a proper child” who understood that not only children, but also their parents, must serve Hashem.
– Rav Yaakov Ahron of Alexzander
