Explanation of Ramban - 25:1, 16:1 - when were parshas Behar (shemita) and Bechukosai (tochacha) said? Three way debate between Rashi, Ibn Ezra and Ramban where these parshas fit in chronologically.

Explanation of Ramban - 23:2 - debate between Rashi/Ramban vs. Ibn Ezra whether 'moadim' includes Shabbos, and discussion of Ramban's insight that davening with a minyan on Yom Tov may be a Torah obligation.

Explanation of Ramban - 19:19 - debate between Rashi vs. Ramban whether there is a reason for the kilayim prohibitions, debate between Ibn Ezra vs. Rambam vs. Ramban what that reason is, discussion of Rashi, Ibn Ezra, Ramban how to translate shatnez, and debate between Rashi vs. Ramban/Tosafos about the details of shatnez

Discussion of Ramban - 18:6, 18:18, 18:19 - debate between Rambam/Ibn Ezra versus Ramban why incest is prohibited, and discussion whether Ramban authored Iggeret Kodesh with a positive attitude towards sexual relations

Explanation of Ramban - 12:2, 12:4, 18:19, Bereishit 31:35 - discussion of Ramban's medical theory that there are toxins in menstrual blood, and the Dvar Avraham of Kovno's 1936 speech defending this notion based on the contemporaneous scientific notion of menotoxins.

Explanation of Ramban - 11:9 - Ramban's stringency that the scales of fish must be peelable, and the debate based on this whether sturgeon and swordfish are kosher, and the story surrounding Noda Biyehuda's permitting sturgeon.

Explanation of Ramban - 1:9 - debate between Rambam vs. Ramban what the reason for animal sacrifice is.

Explanation of Ramban - 7:16 - about Ramban's halachic innovation that even Korban meat which can be eaten for 2 days, there's a mitzva to eat it on the first day specifically. And the Chacham Tzvi's extension of this to the Chagiga of the Seder, that must be able to be eaten on Erev Pesach