Shabbos (Iyun)
Shabbos 3a — Iyun
Why are both the person who picks an object up and the person who sets it down exempt, even though a melacha was clearly accomplished between them? The shiur works through the derivation from "ba'asosah," an apparent contradiction flagged by the Avnei Nezer, and the Rebbe's three-tiered framework (chatzi shiur, chatzi melacha, and kesher she'eino shel kayama) for understanding why hotzaah is a uniquely weak melacha.
Shabbos 3a — Iyun
Why is a person allowed to catch a dangerous snake, or say a charm over it, on Shabbos? The shiur works through the Tur's placement of this halacha among the laws of medicine rather than trapping, the Rambam's view that an unintentional act may not even qualify as a melacha, and the Rebbe's pointed disagreement with the Marcheves HaMishneh over how to read the Rambam.
Shabbos 3a — Iyun
A close read of the Tosafos on Shabbos daf 3 explaining why the Gemara calls certain cases patur u'mutar even though causing another Jew to transgress seems forbidden. Covers the Rogatchover's chakirah on lifnei iver, the din of mesaye'a ledavar aveirah, and the machloket over handing an object that belongs to a non-Jew.
Shabbos 3b — Iyun
When a person's hand sticks out from reshus hayachid into reshus harabim while holding an object, can he pull it back in? The shiur traces Rashi's and Tosafos's differing girsaos (mi kansuha vs. mi asruha) into a full theory of what a karmelit actually is, and whether the Rabbanan can conjure a reshus out of nothing.
Shabbos 3b — Iyun
Picking up the Meiri's kashya on why sticking a hand out of reshus hayachid can still create a chiyuv chatat despite an intervening yedia, then pivoting to the core sugya of Shabbos daf 3: may the Rabbanan permit taking raw dough out of the oven to save someone from a Torah-level violation of baking.
Shabbos 4a — Iyun
An extended analysis of kelutah k'mi shehunach, the principle that an object passing through open airspace is treated as if it had already landed, and the machloket between Rabbi Akiva and the Chachamim over whether this applies. Along the way: a sticky brick stuck to a wall, a beehive thrown into reshus harabim, and Tosafos Yeshanim's view that kelutah can only create liability, never remove it.
Shabbos 4a — Iyun
If someone puts dough into the oven on Shabbos intending to bake it, can he remove it before actually becoming liable? Tosafos's question about hasra'as safek opens into a broader analysis of how a person becomes liable for a melacha that only finishes later, using the famous din of eisho mishum chitzav (fire as a person's arrow) and the Nimukei Yosef's two ways of understanding it.
Shabbos 4a — Iyun
An analysis of the machloket between Rabbi Akiva and the Chachamim over kelutah kemi shehunchah, using a Bava Kama-style chakirah and a ratzo-v'shov mashal to explain why something in mid-flight can be treated as if it came to rest. Moves into the related Tosafos/Meiri sugya of whether moshit is chayav below ten tefachim, and why the Mishkan's wagons carried boards by hand rather than throwing them.
Shabbos 4a — Iyun
Finishing off the sugya of whether a Jew may commit a minor aveirah to spare someone else a worse one, through the machloket of Tosafos, Rashi and the Ritva, and a Magen Avraham/Mishnah Berurah case about sending a non-Jew for an esrog. Closes with the Alter Rebbe's teshuvah on rescuing a kidnapped daughter and the Rebbe's sicha explaining why Pharaoh was punished despite Hashem hardening his heart.
Shabbos 4a — Iyun
Reviewing the Rishonim's dispute over how serious an issur it is to pull raw dough from the oven before it bakes, from Rabbeinu Chananel's Torah-level melacha to the Ramban's reading of the Rif. Then moves to the parallel halacha of a hand stuck out into reshus harabim, tracking the Shulchan Aruch, Alter Rebbe and Biur Halacha through the shogeg/mezid and before/after nightfall distinctions.
Shabbos 4a–4b — Iyun
Working through the Ramban's view that kelutah kemi shehunchah only works because the airspace up to ten tefachim is treated as an extension of the ground, illustrated by the Rebbe's reading of the Beis Hamikdash's outer wall in the Rambam. Returns to the Gemara's question of whether akirah, like hanacha, can manage without a daled-al-daled makom, weighing sevaros from the Maharal and the Rashba.
Shabbos 7a; discussion reaches 8b — Iyun
Working through Ulla's din that an unwalled-for-dwelling karpef bigger than two se'ah is a Torah-level reshus hayachid yet carries a rabbinic karmelit chumra, and the Rishonim's apparent contradictions in Rashi about it. Develops a broader distinction between a place that is truly a reshus hayachid (a cheftza) and a place that merely carries that din, using the kuveret sugya as a parallel case.
Shabbos 9b — Iyun
Opening Shabbos daf 9b's mishnah barring a haircut, bathhouse, tannery or court case samuch leMincha, starting with the Pnei Yehoshua's answer for why it is placed here and the Rambam/Raavad dispute over whether the exemption for something already begun extends to Krias Shema. Then asks whether the samuch leMincha window is itself a din in the time or just a personal issur, and why starting the forbidden activity, even improperly, ends the decree.
Shabbos 9a–9b — Iyun
Closing out the sugya of an askufa standing between a mavoy and reshus harabim, then Rava's din about an object carried through a makom patur and the machloket between the Maharsha and Rabbi Akiva Eiger over whether merely passing by the body counts as a hanachah. Ends by turning the daf to the mishnah restricting eating, bathing or starting business samuch leMincha.