Bava Basra, Chapter 6, Mishnah 4. The Mishnah returns to dealing with cases in which a person makes a transaction without precisely defining its terms, and how we are to understand his intent. This time, we are dealing with two types of cases: a person who buys a plot of land to build a house on it, and a person who hires a contractor to build a house for him. The question is, when the size of the plot or the size of the house is not specified - what is reasonable to expect? Looking into this Mishnah gives us a fascinating glimpse into the lifestyle of the people living two thousand years ago.
"Hamocher makom lachaveiro livnos lo bayis":
The Mishnah deals with two scenarios: "Hamocher makom lachaveiro livnos lo bayis" - Reuven sells Shimon a plot of land so that Shimon can build a house on it; "vechein hamekabel meichaveiro livnos lo bayis" - a person who takes it upon himself, as a contractor, to build a house for his friend. And what kind of house are we talking about?
"Beis chasnus livno" - a small house for a newlywed couple, his son who was just married. This was the custom in those days: the main house was used by the father of the family with his wife and children, and when the sons got married, they would build a small new house nearby, attached to the main house, where the new couple would live.
"Uveis almanus l'vito" - a daughter who was widowed, and possibly has children with her, returns to her father's house. For her too, they build her own small housing unit, a room attached to the family home.
The question is, then: how big is this house?
"Boneh arba amos al sheish - divrei Rabbi Akiva":
According to Rabbi Akiva, the house for a newlywed couple or for a widowed woman, even if she has several children with her, measures four amos by six. An amah is about half a meter, so this means two by three meters - only six square meters. Converted to feet (an amah is about two feet), this is eight by twelve feet. This is tiny: a large eight-seater family car is about two meters wide and five meters long, so the entire house is only a little more than half the area of such a car.
To this, Rabbi Yishmael said: "Refes bakar hu zeh" - it is a cattle shed. In his opinion, the size is too small, and people do not live in such tiny houses; this size of four by six is appropriate for a cattle shed and the like. It is worth noting that Rabbi Yishmael does not specify what the proper size is, but only rejects the size that was set. The halachah follows Rabbi Akiva, and this is what the Shulchan Aruch rules: four amos by six is the appropriate size for a young couple.
And why did the Mishnah specifically mention a son who gets married and a daughter who was widowed?
The Gemara explains that the Mishnah is teaching here derech eretz and proper conduct: it is not proper for a person marrying off his daughter to settle his son-in-law in a house next to his own, because the son-in-law would then be living in the same house as his mother-in-law. Therefore, they do not build a house for a married daughter. But once the son-in-law is out of the picture, the daughter returns to live with her family.
Sizes of other structures:
Cattle shed - if it was agreed to buy land to build a cattle shed, or for a contractor to build a cattle shed, its size is four amos by six.
Small house - six amos by eight, about three by four meters, twelve square meters. This too is a very small size, about the size of what we call a small room today.
Large house - eight amos by ten, about four by five meters, twenty square meters. This is a large room, perhaps the size of the largest room in a house.
Traklin - if one takes it upon himself to build a sort of estate, its size is ten amos by ten, five by five meters, the size of a spacious living room - and in the days of the Mishnah, this was considered an estate.
Regarding the dimensions of the traklin (hall), the Mishnah reveals a sort of aesthetic concept that may have been influenced by the conventions of the classical era in which it was written, specifically Roman and Greek concepts: a square room, as opposed to a rectangular room, is more aesthetically pleasing. Impressive halls are built in this shape, much like the Rotunda in Vicenza, a famous architectural masterpiece built as a square - this is the ideal for a hall.
The Height of the House:
The Mishnah states: "Rumo - kachatzi orko vekachatzi rochbo" - the height of the ceiling is set as half the length plus half the width, or in our terms: the average of the length and the width. For example, a wedding house measuring four by six - the average of four and six is five, so its height is five amos. A large house measuring eight by ten - the average of eight and ten is nine, meaning its height is nine amos, which is a very high ceiling.
The Mishnah brings supporting evidence for this reasoning - averaging the length and the width - from the Heichal. The Heichal, which is also called the Kodesh, refers here to the First Temple, the Temple of Solomon: the Kodesh, which included the Kodesh and the Kodesh Hakodashim, was forty amos long, twenty amos wide, and thirty amos high. Thirty is the average of twenty and forty, meaning that the height of the Heichal was the average of its length and width.
It should be noted that in the Second Temple, this was not exactly the case. In the Second Temple, the entire Heichal structure was much larger, as it included not only the Kodesh and Kodesh Hakodashim - the rear part, as it were, of a T-shaped structure - but also the Ulam in the front, a very high entrance area. However, even if we focus only on the rear section, the Kodesh, although its length was forty and its width twenty like in the First Temple, its height was forty rather than thirty. The reason for this is the prophecy of Chaggai that the Second Temple must be more glorious, meaning larger; and since it was impossible to change the dimensions of the base area, which were transmitted in a separate tradition and had to be exact, they raised the roof and the ceiling in the Second Temple.
"Rabban Shimon ben Gamliel omer: hakol kebinyan Haheichal" - Rabban Shimon ben Gamliel says: everything is like the building of the Heichal:
There are two ways to read his statement:
As a rhetorical question - and this seems to be the simple understanding: Is everything really like the building of the Heichal? Must everyone live according to the impressive dimensions of the Beis Hamikdash? The Heichal had high ceilings because it was an impressive building, but why should a person living in a ten-by-ten-amah hall be required to have a ceiling ten amos high, which is five meters? This seems exaggerated and extreme, and therefore it is not necessary.
As an agreement - some learn, and there are other interpretations brought down, that Rabban Shimon ben Gamliel agrees with the ruling: everything follows the way the Heichal was built, and not anything else.
However, as with all these Mishnayos, the practical halachah in the Shulchan Aruch is determined according to what is usual and accepted in that location. Therefore, if a standard ceiling height is customary, we follow the standard height, whether it is higher than the measure given in the Mishnah or lower.
In summary: In this Mishnah, we learned the dimensions that are assumed when they are not specified in a sales or construction contract: a wedding house for a son and a widow's house for a daughter - four amos by six according to the opinion of Rabbi Akiva, while according to Rabbi Yishmael, this is nothing more than a cattle shed; a cattle shed - four by six; a small house - six by eight; a large house - eight by ten; and a hall - ten by ten. The height of the house is set as the average of its length and width, and the proof for this is from the Heichal, whose height was thirty amos, matching the average of its length and width. In practice - everything follows the local custom.