caring for the poor
"On the night of the 14th [of Nissan], one [begins the] search for chametz". So begins mashechet Pesachim, the tractate dealing with the myriad laws of Passover.
Masechet Shabbat deals primarily with the 39 forbidden activities on Shabbat--especially that of carrying. Yet, as is the norm for Talmudic discussion, one subject leads to another, so that we have a wide range of discussion.