Audio of Lavi on Parshat Noach: Noach (yutorah.org)

Rabbi Ephraim Twersky explains that צדיק היה בדורותיו means that נח didn’t look at the people around him to see if they were better or worse than him because that is a tactic of the יצר הרע, rather he was exactly in his own generation and looked only at himself.

The רל״ג explains that the redundancy in the first פסוק is to praise נח that the ״תולדות״ of נח were that he was ״נח״, always at ease even when other people were bothering him about building the תבה.

Rav Chezkel Abramsky says that ״ותשחת הארץ מפני האלקים״ means that the people on earth didn’t even realize that they were doing something wrong, it was only before ה׳ that the world was being destroyed.   Similarly, the אור תורה says that the פסוק of ״ותמלא הארץ חמס״ teaches us that when you don’t believe in ה׳ you will start being נכשל in בין אדם לחבירו.  Also, the פסוק says ״ותמלא הארץ חמס מפניהם״ and the שער בת רבים explains that מפניהם means that they weren’t embarrassed or ashamed of stealing.

Why does Hashem only call Noach a Tzadick on the second mention when he is saving Noach but in the first mention called him a Tzadik and a Tamim?  1) Rav Moshe Shternbach explains that תמים implies that you do things that are just the simple, easy approach, but ה׳ was saving נח because he took the hard route because it was right. 2) Rav Biderman says that Rashi says the rationale is מקצת שבחו בפניו. However, צדיק is 50%, that is not מקצת, it is more than מקצת! So Rav Biderman explains that really נח was 3 things: he was a צדיק, a תמים and a איש, as the פסוק says ״נח איש צדיק תמים״ because being an איש means you have מידות, so later ה׳ only gave him 33% praise which is מקצת.

Rabbi Gluck explains that it says אלקים a lot of times by נח because אלקים is strict judgement and even by those standards נח was a צדיק.

Rav Moshe explains that ה׳ didn’t initially tell נח how He was going to destroy the world; all He told him was to build the תיבה. Because he wanted to give נח more שכר for building it.

The רל״ג explains that at the end of the פרשה it calls נח an איש אדמה to show the humility of נח.