The **Massechet Baba Batra**, the longest tractate in **Shas** by page count, is the subject of today's study. The discussion begins with a point from the Mishnah concerning a *merzev* and a *mazcheila*. A *merzev* is described as a pipe, akin to a leader, that juts off a roof, directing water into a neighbor's courtyard. The Mishnah states that a *merzev* has no presumptive right, meaning that even if it has been in place for three years, the owner of the courtyard can still demand its removal. This is because the courtyard owner is not considered particular about a *merzev*, so their silence is not interpreted as an agreement for its permanent placement.
However, the Mishnah adds a seemingly contradictory statement: "a *merzev* has no presumptive right, but its place has a presumptive right." The Gemara offers three interpretations to reconcile this. The first interpretation, attributed to **Rebbi Yehuda**, suggests that a *merzev* is movable; it can be placed on the north side or the south side of the roof. Therefore, there is no presumptive right to keep it on a specific side. However, once it is there, the owner of the courtyard cannot demand its total removal. The owner of the roof has a presumptive right to drain water into the courtyard from *some* location. The **Rosh Bam** clarifies that the courtyard owner might need a specific area of their courtyard, allowing them to compel the roof owner to move the *merzev* from one side to another. Yet, the courtyard owner cannot demand its complete removal, as the roof owner has a presumptive right to drain water into the courtyard from either the north or south side, having been allowed to do so for three years.
The second interpretation, from **Rebbi Hanina**, focuses on the length of the *merzev*. If a *merzev* protrudes excessively from the roof, simply allowing it for three years does not grant a presumptive right to maintain that length. After three years, the courtyard owner can demand that it be shortened. However, its position is fixed; it cannot be moved to a different side. This interpretation is stricter regarding the *merzev*'s location than the first. According to the **Rosh Bam**, an overly long *merzev* might significantly intrude into the courtyard's airspace, which the owner might not protest immediately, assuming they can later demand it be shortened. But the specific spot it drains from, if unchallenged for three years, becomes permanent.
The third interpretation, from **Rebbi Yirmiyah Bar Aba**, explains that "a *merzev* has no presumptive right" means the courtyard owner can build directly underneath it. The owner of the courtyard has a right to build upwards in their own airspace. However, "its place has a presumptive right" means the courtyard owner cannot build so high as to damage or remove the *merzev* itself. The **Rosh Bam** explains that allowing a *merzev* to hang in one's airspace does not grant the entire airspace to the *merzev* owner. The courtyard owner can build up to the *merzev*, but not in a way that would necessitate its removal or destruction.
The Gemara then turns to the *mazcheila*, which the Mishnah states *does* have a presumptive right. A *mazcheila* is a long, permanent gutter along the side of the roof. If a courtyard owner sees a *mazcheila* draining water into their courtyard and remains silent for three years, a presumptive right is established. This is because a *mazcheila* is considered a more significant and permanent fixture, and people typically protest against it if they object. Silence, in this case, implies permission.
The Gemara finds this distinction between *merzev* and *mazcheila* consistent with the first two interpretations of the *merzev*. According to the first interpretation, a *merzev* lacks a presumptive right because it is movable, whereas a *mazcheila* is permanent and therefore has a presumptive right. According to the second interpretation, a *merzev* lacks a presumptive right regarding its length (it can be shortened), but a *mazcheila*, being a permanent fixture, cannot be shortened if its size was unchallenged for three years. However, the third interpretation presents a challenge. If a *merzev* has no presumptive right because the courtyard owner can build underneath it, why should a *mazcheila* have a presumptive right, preventing the courtyard owner from building underneath it? What harm would building underneath a *mazcheila* cause?
The Gemara answers that this applies when the *mazcheila* is made of stone. In such a case, the owner of the *mazcheila* can argue that building underneath it would involve hammering and vibrations that could damage or break the stone gutter. Since the courtyard owner remained silent for three years while this expensive stone fixture was in place, they implicitly granted permission, and thus cannot now undertake an action that would destroy it. A *merzev*, even if stone, is considered a less significant item, so its owner might not be particular about potential damage from building underneath.
A new case is introduced by **Shmuel**: what if the owner of the courtyard wants to prevent the roof owner from *clogging* the pipe that drains water into their courtyard? Until now, we discussed the roof owner's right to drain water. Now we consider the courtyard owner's right to *receive* that water. If the courtyard owner has been receiving water for three years, perhaps they have established a presumptive right to it. The **Rosh Bam** explains this as a quasi-transaction: the courtyard owner allowed the water drainage, and the "payment" was the water itself, perhaps used for animals. If so, the roof owner cannot unilaterally stop the flow.
There is a dispute on this matter. **Rav Oshaya** holds that the courtyard owner can prevent the roof owner from clogging the pipe. **Rav Hama**, however, holds that the roof owner can clog it, viewing it not as a business deal but as a favor that can be withdrawn. This dispute involved three generations of scholars: **Rav Oshaya** (grandson), **Rav Hama** (father), and **Rav Bisa** (grandfather). When they presented the question to **Rav Bisa**, he ruled like **Rav Oshaya**, that the courtyard owner can prevent the clogging. **Rami Bar Hama**, observing this discussion, remarked that "a rope that is three strings cannot be ripped so fast," implying the strength of Torah passed through these three generations.
The **Tosafot** questions this, noting that many rabbinic families have seen Torah knowledge depart after several generations. The **Tosafot** explains that the blessing of three generations applies when they studied together and saw each other's learning. This refers to **Avraham**, **Yitzhak**, and **Yaakov**, whose lives overlapped for 15 years, during which they studied Torah together. This established a spiritual guarantee for their descendants. The practical implication is that while Torah doesn't automatically remain without effort, if one shows up and studies, the Torah will return to that family, drawing on the merit of those foundational three generations.
The Mishnah then discusses a small ladder (*sulam ha-metzri*). It states that such a ladder has no presumptive right if placed in a neighbor's courtyard. The owner of the courtyard is not particular about a small, easily movable ladder, so their silence for three years does not grant the ladder owner a permanent right. The Gemara clarifies that this refers to a ladder with fewer than four rungs, essentially a step stool. It's so insignificant that the courtyard owner's silence is not an agreement for permanent placement.
Next, the Mishnah addresses windows. The Mishnah explains what kind of window it refers to, stating it's "small enough that a person's head cannot fit through." The Gemara asks why the Mishnah defined the window but not the ladder. It answers that the window definition is necessary because **Rebbi Yehuda** disputes it, holding that even a small window with a border *does* have a presumptive right. Since there's a dispute, the Mishnah needed to specify the case.
The core issue with a window is *Hezek Re'iyah*, the damage of sight or privacy. A neighbor might object to a window that allows the other to look into their courtyard. **Rebbi Zira** discusses a *Halon Suri* (a large window). If such a window is built less than four cubits from the ground, and the courtyard owner remains silent for three years, a presumptive right is established. This is because a large, low window clearly allows viewing into the courtyard, and silence implies permission. If the neighbor then wants to build a wall blocking this window, they cannot. However, the neighbor *could* have protested initially to prevent the window from being built. Conversely, if the window is built *more* than four cubits high, **Rebbi Zira** holds it has no presumptive right, and the neighbor cannot prevent its construction. This is because a high window does not typically allow for viewing into the courtyard, so there is no *Hezek Re'iyah*.
**Rebbi Elah** disputes this. He holds that even a large window more than four cubits high has no presumptive right, meaning the neighbor can later build a wall to block it, even if they were silent for three years. However, **Rebbi Elah** also holds that the neighbor *can* initially prevent the construction of such a high window. The Gemara explores whether this dispute revolves around *Midat Sedom*. **Rebbi Zira** believes one can be compelled not to act like the people of Sedom, meaning if building a high window causes no damage, the neighbor cannot prevent it. **Rebbi Elah**, however, believes one *cannot* be compelled on *Midat Sedom*, so even if there's no direct damage, the neighbor can still protest the high window.
The Gemara ultimately rejects this explanation of *Midat Sedom*. It concludes that everyone agrees one can be compelled not to act like the people of Sedom. Instead, the dispute regarding high windows centers on the potential for *Hezek Re'iyah*. **Rebbi Elah** is concerned that even a high window could pose a privacy risk if the window owner places a chair or step stool to climb up and look into the courtyard. **Rebbi Zira** dismisses this, considering it an abnormal use of a high window, and therefore not a basis for preventing its construction. Thus, for **Rebbi Zira**, a high window causes no damage, so its construction cannot be prevented, and it gains no presumptive right against being blocked later. For **Rebbi Elah**, even a high window carries a potential for *Hezek Re'iyah*, justifying initial protest, but if built, it still doesn't gain a presumptive right against being blocked.
**Shmuel** introduces a new point: a window built specifically for light, even a small one, *does* have a presumptive right. Unlike windows for viewing, a window for light is considered a permanent and essential fixture. The neighbor, seeing a window built for light, understands its permanent nature. If they remain silent for three years, they cannot later demand its removal or block it. This distinction highlights that the *intention* behind the window's construction affects its halachic status.
The Mishnah then discusses a *ziz*, a piece of wood or beam protruding from a wall. If a *ziz* protrudes one handbreadth (*tefah*), it has a presumptive right. This means if it has been there for three years, the courtyard owner cannot build a structure that blocks it. The **Rosh Bam** explains that a *ziz* of this size is significant enough that silence for three years implies permission. If it protrudes less than a *tefah*, it has no presumptive right. The courtyard owner can build and block it, as such a small item is considered insignificant, and silence does not imply permission. The Mishnah adds that in this case, the courtyard owner "cannot protest." The Gemara clarifies that this means the *roof owner* cannot protest the *courtyard owner* building to block the *ziz*. However, the courtyard owner *can* initially protest the roof owner putting up even a small *ziz*.
This leads to a dispute about *Hezek Re'iyah* concerning a *ziz* less than a *tefah*. One opinion holds that *Hezek Re'iyah* is always a concern, so the courtyard owner can protest the *ziz*'s initial placement. The other opinion argues that such a small *ziz* is only useful for hanging items, which can be done without looking into the courtyard (e.g., by turning one's head). Therefore, there is no *Hezek Re'iyah*, and the courtyard owner cannot prevent its initial placement. The counter-argument is that the roof owner might be nervous about falling and instinctively look straight, thus inadvertently looking into the courtyard.
**Rebbi Asi** in the name of **Rebbi Mani**, and others in the name of **Rebbi Yaakov** in the name of **Rebbi Mani**, made a statement: "If it has a presumptive right with a *tefah*, it has a presumptive right with four." This seemingly strange statement is explained by **Rebbi Yahi**. The basic rule is that a space of four by four *tefahim* is considered a significant area. If a *ziz* is one *tefah* wide and protrudes four *tefahim* into the courtyard, and the courtyard owner remains silent for three years, the roof owner gains a presumptive right not just for that specific *ziz*, but for a four-by-four *tefah* space. This means they can extend the width to four *tefahim* as well. Similarly, if it was four *tefahim* wide and protruded one *tefah*, it could be extended to four *tefahim* of protrusion. However, if it only protruded three *tefahim*, even if it was one *tefah* wide, no presumptive right for a four-by-four space is established, as it hasn't reached the threshold of four *tefahim* in any dimension.
The next Mishnah states that one may not open windows into a shared courtyard (*Chatzera Shutefim*) nor open a door into it from an adjacent house or upper story. The Gemara asks why the Mishnah specifies "shared courtyard"; surely one cannot open a window into a *friend's* courtyard either. The answer is that it's a novel teaching: one might think that in a shared courtyard, since partners already see each other while working there, an additional window would not constitute further *Hezek Re'iyah*. However, the Mishnah teaches that it *does* constitute additional damage, as it forces the partner to maintain privacy even when the other is merely in their house, not just when both are in the courtyard.
Regarding opening a door from an adjacent house into a shared courtyard, this is forbidden because it increases traffic, burdening the shared space. Similarly, if one builds an upper story (*aliya*) above their house, they cannot open a door from that upper story into the shared courtyard. An upper story is considered a new dwelling, bringing new inhabitants and thus more traffic into the shared space. However, one *can* divide their existing ground-floor house into multiple rooms or create a loft within the existing ceiling height, provided access to the courtyard remains through the original ground-floor entrance, as this does not add new dwellings or increase traffic into the shared courtyard.
The Gemara brings a story: a man opened windows into a shared courtyard. He came before **Rebbi Ishmael bar Rabbi Yosef**, who told him, "You have a presumptive right." This implies an immediate presumptive right if the partner saw the construction and did not protest. However, another sage, **Rabin Nahman**, ruled differently. He said, "You toyed with yourself to open the window, now toy with yourself to close it." This indicates that a presumptive right requires three years, and initial silence is not enough. **Rabin Nahman** further states that if a window owner, after three years, sees their neighbor build a wall blocking their window and remains silent, the presumptive right is retroactively lost. This is because it is not in a person's nature to remain silent when their window, for which they supposedly had a presumptive right, is blocked. Such silence immediately negates the prior presumptive right.