Class 1: Moshe takes out Yosef’s remains. He does this 1) because they swore not to leave without them 2) Because it gave us -Yidden the strength needed to survive the Midbar.
part one
Class 2: The Rebbe takes an old and obscure idea and makes it shine. In this case, the Tzemach Tzedek’s mention that Yosef was named Yosef to denote making from and אחר a foreigner a בן a son for Hashem.
Part two
Class 3: Inside: going into the desert requires special strength that comes from Yosef.
