These are the generations of Noach: Noach was a just man in his generation (Gen. 6:9)
Rashi comments: This verse teaches us that the most important legacy of a righteous person is his good deeds. A righteous person is not defined by his lineage or by his noble ancestry, but by his own actions and behavior. (Divrei Yisrael)
A window shall you make for the ark (Gen. 6:16)
The Hebrew word for "ark" is "tayva," which also has the meaning of "word." A Jew's job is to make a "window," as it were, for the words he utters in prayer or in the study of Torah, and to let them illuminate, as the sun shines at midday. (Baal Shem Tov)
I will bring a flood of waters upon the earth, to destroy all flesh (6:17)
Why did G-d choose a flood with which to punish mankind? Could he not have chosen another method to destroy the wicked? The purpose of the flood, however, was to purify the world which had become unclean and defiled by its inhabitants. This is alluded to in the duration of the flood, forty days, and the requirement that a purifying mikva (ritualarium) contain at least forty sa'a (a specific measure) of water. (Rabbi Shneur Zalman)
And Noach went in, and his sons, and his wife, and his sons' wives into the ark (7:7)
A person should not content himself with his own entrance into the "ark"-the holy letters of prayer and of the Torah, but should always seek to bring others with him as well, not only members of his family but every fellow Jew. Just as G-d helped Noach by closing the door of the ark after all were safely inside, so, too, is every Jew assisted by G-d when he comes to the aid of his fellow man. (Lubavitcher Rebbe)
And only Noach was left (7:23)
Despite the fact that Noach was a righteous person, he was still required to tend to all the animals in the ark and take care of their needs. This was a physically demanding and sometimes dangerous job. Similarly, no matter how high a spiritual level one reaches, he is still obligated to take care of those around him who may need his guidance. (Likutei Sichot)
Reprinted from the Parashat Noach 5763/2002 edition of L’Chaim