Beitzah 16a and Beitzah 16b, honoring Shabbat and what aspect of Shabbat was kept as a private matter between Gd and the Jewish people, and then some rules of eruv tavshilin, what foods can count for it, how much it needs to be, and whether one person can make it for others. Closing with the question of whether one can make an eruv hatzerot on a Friday that’s also a holiday.
