Sending gifts on yom tov - if the principle was that anything that can be used on yom tov can be sent, then why does the Gemara say - anything that can be used on a regular day, not just yom tov, can be sent on yom tov?! Which introduces several cases of one who wears tefilin in the say of Erev Shabbat or erev yom tov, and when it gets dark, hides the fact that he's wearing tefilin. Of course, tefilin are a precious commodity, and need careful protection, from the elements, perhaps, but also from thieves, even Jewish ones. Also, the second perek! Which is largely about Eruv Tavshilin. Which provides the loophole that allows for preparation on yom tov for Shabbat. All of which safeguards Shabbat. And provides respect for the holiday. Plus, a story about R. Eliezer's class in yom tov, and a discussion of how to celebrate yom tov, and the responsibilities of the eruv tavshilin.