Megillah 5a and Megillah 5b, why we observe certain things early (like reading Megillah) and push off others (like fasting), and the prohibition of labor on Purim, either day.
Megillah 5a and Megillah 5b, why we observe certain things early (like reading Megillah) and push off others (like fasting), and the prohibition of labor on Purim, either day.