Concepts: 430 years of exile began with Avraham, because he felt anguish over news of the exile; empathy of Moshe Rabbeinu; Shevet Levi did not receive spoils of Egypt, yet leaders were from shevet Levi;  Shabbos Hagadol — practical halacha; reading hagadah on Shabbos; physical and spiritual exile began and ended at different times.