Why does the Torah write yet again that Noach did what HaSh-m instructed him?
Ramban: This time, Noach fulfilled the command of taking all the animals into the Ark in pairs.
Why did HaSh-m have to close [the door of the Ark] behind Noach ("va'Yisgor HaSh-m Ba'a'do")? Why couldn't Noach do it himself?
Rashi, Targum Onkelus and Targum Yonasan: The Torah does not only mean that HaSh-m closed the door behind him, 1 but that He protected him from the people outside who threatened to smash the Ark if he entered it. 2 When they tried to carry out their threat, wild animals killed them.
Moshav Zekenim #1: HaSh-m's Name closed it, so it could not be opened.
Moshav Zekenim #2: HaSh-m stopped the water from entering the Ark.
QUESTIONS ON RASHI
Rashi writes:"HaSh-m protected Noach so that [his detractors] would not demolish the Ark...." What is the source for this in the Pasuk?
Gur Aryeh: The word "Ba'a'do" seems to be out of place here, and must mean "surrounding him." Rashi therefore explains that HaSh-m surrounded the Ark with lions etc.
Rashi writes: "... But the simple meaning of the verse is that He closed [the door] opposite him." What does Rashi mean?
Gur Aryeh: It is unnecessary to explain "Ba'a'do" as "surrounding" (refer to 7:16:2.1:1), for we have many Scriptural examples in which "Ba'a'do" means "opposite," or "facing." Here too, HaSh-m closed the door opposite Noach to keep out the water.