Explanation of Ramban - 12:10, 12:11, 20:2, 20:12 - discussion of Rashi, Ramban and Ran's approaches to the two incidents with Pharoah and Avimelech where Sarah is taken by the king, and the differences between them

Explanation of Ramban - 12:7, 15:1, Shemos 12:40 - discussion between Rashi, Tosafos, Ibn Ezra, Ramban and Vilna Gaon, whether Bris Bein Habesarim (ch. 15) happened when Avraham was 70 years old, before Lech Lecha (12:1), or afterwards when he was 75 years old

Explanation of Ramban - 1) 6:18 - debate between Rashi, Ibn Ezra and Ramban what the covenant mentioned to Noach is, 2) 9:12 - debate between Rashi/Ibn Ezra vs. Rav Saadia Gaon/Ramban (and other commentators) whether rainbows are a natural occurence or a miraculous event

Explanation of Ramban - 1) 4:17 - did any of Cain's descendants survive the flood, 2) 4:22 - three views in the midrash what was significant about Naamah, 3) 4:23 - debate with Rashi/Ibn Ezra why Lemech's wives separated from him.

Explanation of Ramban - 1:6, 1:8, 1:10 - debate between Rashi/Ibn Ezra vs. Rambam/Ramban whether the Shamayim in verse 1:1 is the spiritual Heavens or the physical Sky

Explanation of Ramban - 20:10, 20:11, 29:10 - debate between Rashi vs. Rambam/Ramban whether Canaanite nations can surrender, and discussion of why the Gibeonites had to lie to surrender and not do so openly? Rambam, Tosafos and Ramban's answers.

Explantion of Ramban - 23:5, 23:7 - debate between Ibn Ezra and Ramban whether Moav gave the Jewish people food and water, and what it means not to offer them peace.

Explanation of Ramban - 15:1 - debate between Rashi, Ibn Ezra and Ramban what 'miketz' means, and when hakhel and cancelling the debts in shemitah happens.