Days on the Jewish Calendar: Introduction
The Secret of the Leap Year
Explains the mechanics of why the Jewish calendar needs a leap year to keep Pesach in the spring, then develops the deeper meaning behind calling a leap year a shanah temimah, a year of going beyond 100 percent avodah into the level of b'chol meodecha, serving Hashem without limit the way a Yid can transcend even the framework of mesirat nefesh. Unpacks the Kabbalistic idea of two types of Godly light, the strong but unabsorbed ohr sovev kol almin represented by the sun, and the weaker but internalized ohr memale kol almin represented by the moon, which every mitzvah briefly unites as yichud Kudsha Brich Hu u'Shechinteih. Closes by applying the sun and moon to two ways of serving Hashem, the tzaddik's constant, unchanging light against the ordinary person's fluctuating but ever-renewing pleasure, and explains why a leap year makes it easier to combine firm, unwavering commitment with the constant growth of a mekabel who never stops wanting more.
The Jewish Calendar
Explains why the Jewish calendar follows the moon rather than the sun, tying it to the Gemara's comparison of Klal Yisrael to the moon's own cycle of decline and renewal, before working through the technical mechanics: a 29.5-day lunar month, a 354-day lunar year, and the 19-year machzor that reconciles it with the solar seasons through leap months. Walks through how the Sanhedrin sanctified each month by witnesses testifying to the new moon, until Hillel HaNasi fixed the calendar through the end of days, and traces the torch-and-messenger system that produced the custom of a two-day Yom Tov outside Eretz Yisrael — with Shavuos as the one exception whose second day rests on a vadai derabanan rather than a safek d'oraisa. Closes with why Rashi calls Kiddush HaChodesh the 'first mitzvah,' what it proves about Torah SheBe'al Peh, and the Yerushalmi's teaching that a beis din's calendar ruling can retroactively reshape a person's physical halachic status, since bringing kedusha into time itself is an even deeper avodah than bringing it into a physical object.
The Mystical Significance of 3 Matzos and 4 Cups of Wine
Opens with the halachic sources for eating three matzos and drinking four cups of wine at the seder, then addresses the Mordechai's question of why the four expressions of geulah are marked by wine rather than by a fourth matzah. Explains that matzah, tasteless and min haTorah, represents the part of the redemption that came purely from Hashem before the Jews were ready, while wine, flavorful and mid'rabbanan, represents the elevation they achieved themselves by the time of Matan Torah. Develops the Kabbalistic meaning of the letters gimel and dalet as mashpia and mekabel, paralleling the three avot and four imahos, and closes with a Q&A touching on the unused fifth cup of wine and why matzah is also called lechem haemunah.
The Sale of Chometz
Traces the halachic development of selling chometz before Pesach, beginning with the unique issur of bal yeira'eh u'val yimatzei and the two Torah-level solutions of biur and bittul, through the Mishnaic option of an outright sale to a non-Jew. Follows how, once Jewish-owned breweries left large stockpiles of chometz, the Bach's innovation of selling the premises along with the chometz, avoiding the problem of achrayus, evolved into the modern communal sale conducted through a rav, and addresses the Shoel U'Meishiv's halachic objections to a single mass mechirah. Devotes extended attention to the Alter Rebbe's requirement of an arev kablan rather than a mere deposit, the roiah b'kiyumo problem it raises, and the full stack of kinyanim, kesef, shtar, agav, mesiras maftechos, that make the sale a real, enforceable transaction rather than a legal fiction.