Commentary for Bava Batra 1:6
אֵין חוֹלְקִין אֶת הֶחָצֵר, עַד שֶׁיְּהֵא אַרְבַּע אַמּוֹת לָזֶה וְאַרְבַּע אַמּוֹת לָזֶה. וְלֹא אֶת הַשָּׂדֶה, עַד שֶׁיְּהֵא בָהּ תִּשְׁעָה קַבִּין לָזֶה וְתִשְׁעָה קַבִּין לָזֶה. רַבִּי יְהוּדָה אוֹמֵר, עַד שֶׁיְּהֵא בָהּ תִּשְׁעַת חֲצָאֵי קַבִּין לָזֶה וְתִשְׁעַת חֲצָאֵי קַבִּין לָזֶה. וְלֹא אֶת הַגִּנָּה, עַד שֶׁיְּהֵא בָהּ חֲצִי קַב לָזֶה וַחֲצִי קַב לָזֶה. רַבִּי עֲקִיבָא אוֹמֵר, בֵּית רֹבַע. וְלֹא אֶת הַטְּרַקְלִין, וְלֹא אֶת הַמּוֹרָן, וְלֹא אֶת הַשּׁוֹבָךְ, וְלֹא אֶת הַטַּלִּית, וְלֹא אֶת הַמֶּרְחָץ, וְלֹא אֶת בֵּית הַבַּד, עַד שֶׁיְּהֵא בָהֶן כְּדֵי לָזֶה וּכְדֵי לָזֶה. זֶה הַכְּלָל, כָּל שֶׁיֵּחָלֵק וּשְׁמוֹ עָלָיו, חוֹלְקִין. וְאִם לָאו, אֵין חוֹלְקִין. אֵימָתַי, בִּזְמַן שֶׁאֵין שְׁנֵיהֶם רוֹצִים. אֲבָל בִּזְמַן שֶׁשְּׁנֵיהֶם רוֹצִים, אֲפִלּוּ בְפָחוֹת מִכָּאן, יַחֲלֹקוּ. וְכִתְבֵי הַקֹּדֶשׁ, אַף עַל פִּי שֶׁשְּׁנֵיהֶם רוֹצִים, לֹא יַחֲלֹקוּ:
The courtyard is not divided until there are four cubits to each (partner). [One partner in the courtyard cannot compel the other to divide it until each has four cubits aside from the doors, each house in the courtyard requiring four cubits before the door for unloading an ass. Aside from those four cubits, an additional four cubits are required for their other purposes before the courtyard becomes subject to partition.] And a field (is not divided) until there are nine measures to each. R. Yehudah says: Until there are nine half-measures to each. [Each speaks of his own place, and they do not differ. For a nine half-measure field in the place of R. Yehudah yielded as much as a nine measure field in the place of the rabbis.] And not a garden until there is a half-measure to each. R. Akiva says: A space to sow a quarter measure. [The halachah is that fields awaiting plowing or sowing are not subject to partition until there remains for each of the partners enough land for one day of plowing, or sowing, or the like.] Nor (do they divide) a traklin or a moran [spacious dwellings], nor a pigeon coop, nor a garment, nor a bath-house, nor an olive press, until there is enough for each. [As explained below: so that after they divide and each takes his share there remains enough for each that it be called "traklin" or "moran" (or the like), i.e., that there remain in the part the name by which the whole was called.] This is the rule: Something which retains its name when it is divided, is divided; if not, it is not divided. When is this so? When both do not wish to divide. [One cannot compel the other to divide against his will; but he can compel "god or agod," i.e.: Buy my part or sell me your part for what it is worth.] But when both wish (to divide), even with less than this (i.e., what is stipulated above) they may divide. And with The Holy Scriptures [Torah, Prophets, and Writings], even if they both wish to do so, they may not divide. [This, only with one volume; but with many separate books, they may divide if they so wish.]
Bartenura on Mishnah Bava Batra
English Explanation of Mishnah Bava Batra
Nor [do they divide up] a field until it has nine kavs for this [partner] and nine kavs for this [partner]. Rabbi Judah says: “Until it has nine half-kavs for this [partner] and nine half-kavs for this [partner].
Nor [do they divide up] a garden until it has a half-kav for this [partner] and a half-kav for this [partner]. Rabbi Akiva says: “A quarter-kav.”
Nor [do they divide up] an eating hall, a watch-tower, a dovecote, a cloak, a bathhouse, or an olive-press until there is sufficient for this [partner] and for this [partner].
This is the general rule: whatever can be divided and still be called by the same name, they divide; otherwise they do not divide.
When is this so? When they do not both wish [to divide the property]. However, if both wish they can divide it even if it is smaller. And with regards to the Sacred Books, they may not be divided even if both are willing.
Mishnah six returns to discuss a subject which began in mishnah one. There we learned the laws of building walls in shared courtyards, gardens and valleys. Mishnah six discusses which jointly-owned properties can be split into two parts.
This mishnah is quite straightforward so we will explain it briefly. Sections four and five basically summarize the laws of splitting jointly held property. One partner can force another partner to split the property only if the remaining property will still be sufficiently large to use it for its intended purpose. For instance if partners jointly own a dovecote (a place for breeding and storing pigeon doves) and one partner wants to split it, there must be enough room in each half for both partners to use it as a dovecote. Furthermore, section five clarifies that each half must be able to be called by its previous name. For example, if partners owned a truck one could not force the other to take half of the truck, since half a truck is worthless. If, however, partners owned an iron mine, one could force the other to take half, as long as each half was large enough to be an iron mine in its own right. The first three sections of our mishnah give concrete sizes with regards to courtyards, fields and gardens, but the principle applied is basically the same as that in sections four and five.
Section six emphasizes that the first five sections are true only as long as one partner does not agree to split the property. If, however, both parties agree to split the property they can split an even smaller piece. The one exception to this rule are scrolls containing the books of the Bible. It would not be respectful to the Sacred Books to cut a scroll in half. If, however, the books are in separate scrolls partners could divide them. [Note, in the time of the Mishnah all books were written in scroll form. The modern codex was not yet invented.]