Classes by Mordechai Dinerman

A dangerously ill person needs to eat chicken on Shabbos, and nonkosher is available. Do you feed him the nonkosher chicken, or slaughter one properly and violate Shabbos? The Raavad’s answer survives in conflicting versions, and the Ramban left a blank space when reaching this topic. We’ll discuss how that happened, then follow the debate across two centuries. We’ll find that in France and German...

How and when did the bris take the shape we recognize today? When did the sandek and kvatter enter the ceremony, and what do those words even mean? Today’s class traces the development of the bris in Ashkenaz between the twelfth and fifteenth centuries. We’ll explore the origins and context of its specialized terms, the deals people made to secure coveted honors, a controversial practice that the...

Today we pick up where we left off: it's just before Rosh Hashanah 1904, and Rabbi Akiva Yosef Shlesinger's plan to sound the shofar on Shabbos looks promising. Today we find out what actually happened that Rosh Hashanah and why, and how the conversation carried on through the following year, up to Rosh Hashanah 1905, which was also on Shabbos. And finally, we’ll reach the last scene of th...

As Jews prepared for Rosh Hashanah 1904, Rabbi Akiva Yosef Shlesinger took up his pen and wrote to a rabbinic journal in Hungary, laying out why he believed the shofar should be sounded on Shabbos despite the rabbinic ban. In this class, we examine his account of the attempt leading up to Rosh Hashanah 1882, and then again leading up to Rosh Hashanah 1904. We'll trace the steps he took, the ha...

A man wrote to the Tzemach Tzedek, the third Rebbe of Chabad, about fears he couldn’t shake in matters of health and money. What came back was a long letter working through Torah sources to explain how fear takes hold and how to loosen its grip. This class takes this remarkable letter line by line, setting the scene, tracing the sources, and drawing out what it asks of us today. ⁠Click here for th...

HaRav Levi Yitzchak Schneerson spent his final years in exile in Kazakhstan, banished there by the Soviets for his work strengthening Jewish life across the Soviet Union. Soon after arriving there in 1940, he wrote a brief account of his imprisonment. It reads like no ordinary memoir: each line is a kabbalistic commentary on his own life, shaped by a deep belief in personal divine providence. Gath...

In 1612, Avraham Portaleone of Mantua published a landmark work of encyclopedic proportions covering all things Beis Hamikdash. Reading through four of his discussions, we meet a man working under far-from-ideal conditions. His sefer turns out to be part of a larger story about the struggles of Jewish printing and book possession in sixteenth- and seventeenth-century Italy. The Rabbi-Doctor Who Wr...

In 1790, Moses Seixas of Newport, Rhode Island, and Manuel Josephson of Philadelphia corresponded, with Josephson composing what effectively amounts to a halachic teshuvah. Josephson raised concerns about the conduct of the Touro Synagogue in Newport, arguing that elements of the service were not being properly observed. The exchange provides an important window into the religious commitments and...

In this final class of the series, we will examine the Rebbe’s statements and correspondence regarding going up to Har Habayis. By studying the available sources, we will seek to better understand what the Rebbe did—and did not—say about this complex and significant question. This is the fourth and final installment on this topic.  What Did the Rebbe Say About Going on Har Habayis?

Whether Jews may enter Har Habayis largely depends on whether we know where the Beis Hamikdash stood. A common assumption is that we don’t know for sure, but that assumption has a history. This class traces the story of this uncertainty, primarily through the accounts of Jewish travelers who visited Eretz Yisrael and recorded what they saw and heard. This is the third installment in a series about...

The bar mitzvah ceremony didn’t always look the way it does today. In fact, for much of Jewish history, it barely looked like anything at all. In this episode, we investigate: When did a ceremony first appear? What did it look like? When did bar mitzvah boys start receiving an aliya? Leining? Leading davening? A derasha? We’ll trace its evolution among Ashkenazi Jews from the eleventh century thro...

In the spring of 1096, crusading armies swept through the Jewish communities of the Rhineland, leaving devastation in their wake. This class traces how those events gave rise to rituals of memory. In the community of Worms, fast days were proclaimed on the 23rd of Iyar and Rosh Chodesh Sivan, accompanied by elaborate mourning customs. We’ll see how in 1716, when Rosh Chodesh Sivan fell on a Friday...

In the late 1920s, a Jerusalem rabbi cited an obscure passage describing a certain Rabbi Moshe’s pilgrimage to the Holy Land, including what appeared to be a visit to the Temple Mount itself. He seized on it as proof that going there was halachically permitted. This sparked a fierce debate over the passage: Was it even credible? Who exactly was this Rabbi Moshe? Did the text actually refer to the...

Mechiras chametz is today a standard part of observing Pesach. But how did this practice come to be, and how has it evolved over the centuries? In this class, we analyze the relevant sources in Ashkenazic and Sefardic texts, revealing two distinct approaches to this topic. We’ll then find how the more the sale was refined to accommodate the seller, the more complications it introduced, requiring a...

There’s a well-known story about Sir Moses Montefiore going up onto Har Habayis during one of his seven legendary trips to Eretz Yisrael. But once you begin looking into it, you quickly discover that there are several versions of the story, each one telling it a bit differently: when he went up, why he did it, how he did it, and what the rabbinic community’s reaction was. As we’ll see, a great dea...

The Mishneh Torah printed in Venice in the 1570s was the product of a broad and deliberate program of censorship. Beyond removing the handful of references to the Christian founder, which we discussed in the prior class, the censors altered many other words and phrases. In some places, entire laws disappear; in others, the language is carefully adjusted to soften its force. In this class, we trace...

In October 1949, The   New York Times announced a sensational discovery: an ancient manuscript of Mishneh Torah was discovered and it contained a long-lost provocative passage about the Christian founder. The headline sparked excitement, but the story was riddled with errors. In this class, we trace the real history of that controversial passage and examine when, how, and why it was cut by the cen...

The class follows the paper trail in Rabbi Yosef Caro’s  Kesef Mishneh  to reconstruct how and when this major commentary actually came into being. After examining its printing history and the author’s stated purpose, the discussion turns to a key flashpoint: whether  Kesef Mishneh  represents Rabbi Yosef Caro’s final halachic word. We work through the evidence—internal cross-references, page numb...

Today, we explore Jewish life during Prohibition, when the manufacture and sale of alcoholic beverages were banned in the United States. While the U.S. government granted religious exceptions for wine, both the Reform and Conservative movements distanced themselves from this loophole, endorsing the use of grape juice instead. One contemporary posek passionately rejected grape juice, and we’ll exam...

This class takes us inside the Jewish wine economy of earlier centuries. We will see communities enforcing price ceilings, outlawing seller collusion, and appointing assessors to protect community members from being overcharged. In some places, the system became so aggressively strict: monopoly-style selling rights, blind tastings, barrels sealed by wine assessors, community-owned measuring jugs,...

In the mid-1860s, a wave of rabbinic correspondence swept across central and eastern Europe as leading rabbis grappled with a vexing dilemma: how to respond to an antisemitic trial that touched directly on core points of Jewish theology. This case pitted antisemites against Jews, and within the Jewish community, enlightened progressives against traditionalists. Navigating this reality proved deepl...

In this final class of the series, we explore the Rebbe’s comments about Israel’s lopsided hostage deals during the late 1970s and 1980s, alongside the perspectives of other poskim during that period. The Hostage Dilemma: Part IV (Israel, 1979–1987)

In this class (third of a four-part series), we look at the halachic debate over freeing hostages as it unfolded in Israel during the 1970s. After the September 1970 triple hijacking, several poskim weighed in on whether it was permitted to meet the terrorists’ demands. The discussion resurfaced a few years later after the Yom Kippur War, and then again in the wake of the famous Entebbe raid in 19...

Today, we’re returning to the topic of hostages in Jewish history. Last time, we spent most of our attention on the exceptions to the rule. This time, we’re looking at cases where the Mishnah’s ban on overpaying played at least a partial role in shaping actual halachic decisions and communal policy. And yet, as we will see, the overarching conclusion that we reached in the prior class will hold: o...

This class takes up one of the most challenging moral questions in Halachah: how far should we go to redeem captives? We’ll look at how this issue unfolded in Jewish communities around the world during the fifteenth and sixteenth centuries—what actually happened, and how the poskim grappled with the Mishnah’s rule against paying more than market value. In a future class, we’ll revisit this topic i...