Explanation of Ramban - 1) 5:15, 16:12 - debate between Rashi/Ibn Ezra versus Rambam/Ramban regarding the two different reasons for Shabbos in the Ten Commandments. 2) 4:19, 32:12, Shemos 12:12, Vayikra 18:25, Bamidbar 11:16, 14:9, 23:23 - Ramban's theory about the mistake of idolatry.