Class One. This part of the Ma’amar deals with the meaning of בסוכות תשבו שבעת ימים. Taking something that is in and of itself temporary and making it permanent. It is true of סוכה and of all Mitzvos. It is -really- the prescription for דירה בתחתונים.
Class Two. In this class the discussion is about כל האזרח בישראל ישבו בסוכות. The Rebbe explains that this is a reference to the Yechida. Though it will be revealed primarily when Moshiach comes we can have a taste of this now too.