The eighth Mishnah in the fourth chapter of Tractate Bava Basra continues with the same topic: a person who sells his field and does not specify exactly what is included in the concept of a "field." The Mishnah lists the items that are automatically included in the sale, as opposed to those that are considered independent entities and are not sold with it.
The items included in the sale:
"Hamocher es hasadeh - mechar es ha'avanim shehen letzorkah" - ordinary stones lying in the field are not part of it: they are detached from it and are not essential to it, and in principle, the seller may take them with him to build his new house. However, stones that were designated and intended for the needs of the field, such as for building a fence around it - a common practice in fields - are sold with it, even if the fence has not yet been built from them.
"Ve'es hakanim shebakerem shehem letzorkah" - the rule also applies to a vineyard within the agricultural area being sold (and we will set aside the matters of kilayim in a vineyard here). The reeds are poles and stakes stuck in the ground and used for training the vines. The vines themselves are included in the sale of the area; reeds that have not yet been designated for use and are merely lying there are not included. But reeds standing for the needs of the vines, whose purpose is evident and are already placed in their location, are included in the sale.
"Ve'es hatevuah shemechuberes lekarka" - produce growing in the field, as long as it is attached to the ground, is part of the field and is sold with it. This is true even if it has fully ripened, and even if the time for harvesting has already passed, the seller cannot separate his produce from the field. However, produce that has been harvested and detached from the ground is not included in the sale.
"Ve'es mechitzas hakanim" - and the reed partition:
A section in the field where reeds grow - like a bamboo thicket - is included in the sale when it is small, meaning less than a beis rova. A beis rova is an area of ten and a half amos by ten and a half amos, about a hundred square amos, which is approximately five meters by five meters, or about twenty-five square meters. Because it is a small section, it is not considered a separate place and people do not treat it as such. But if it was larger than a beis rova, it is an independent area and is not included in the field, and the seller retains the thicket of reeds and stalks standing there for himself.
Why is it called a "partition"? The Meiri explains that it was customary to plant plots of reeds, stalks, or tall grasses to mark where one person's field ends and his neighbor's field begins, and hence the name partition.
In any case, a thicket larger than a beis rova is not included in the sale even if it is situated in the middle of the field. We will yet discuss how the seller will access his spot, but the concept is similar to what was stated at the beginning of the chapter: one who sells a house does not necessarily sell the cistern in its cellar, but rather retains it for himself, even though it is located with the house and even though it is underneath it. Here too, a large thicket standing in the middle of the field is an independent entity and is not sold.
"Ve'es hashomerah she'einah asuyah betit" - and the watchman's booth that is not made with clay:
A small watchman's booth, which serves the watchman guarding the fields, like a simple sukkah that is not made with clay - it is temporary and insignificant, it is not a substantial structure, and it is subordinate to the field, and therefore it is sold with it. But if it was made with clay, clay on the roof and clay on the walls, making it like a permanent structure - it is an independent structure that is not included in the sale, even though its purpose is to serve the watchman of the field.
"Ve'es hecharuv she'eino murkav, ve'es besulas hashikmah" - and the un-grafted carob tree, and the virgin sycamore:
All the trees in the field are included in the sale, but particularly large trees are considered too significant to be included. Practically, this refers to two types of trees: the carob and the sycamore. The carob tree is a large tree; in the Land of Israel today, the largest trees seen in the fields and around the center of the country are carob trees, and they can reach a height of about fifteen meters when they are robust. The shikmah, which is often translated as the sycamore tree, is actually called a sycamore-fig, and in truth, it is a species of fig tree and not a sycamore tree. It is even larger, and can reach a height of twenty meters. These significant trees were used to produce wooden beams for building.
The Mishnah says: a small tree, even a carob or a sycamore, is included in the sale; but a large, mature tree in which effort has been invested - stands on its own. And how do we define what is a large, mature tree in which effort has been invested? The Mishnah states: "Hecharuv she'eino murkav" - a carob onto which other branches have not yet been grafted. This has no connection to the laws of kilayim, rather it is a different point: a tree that serves as rootstock and a base for grafting branches that will grow further represents too much investment, and is too large and significant to be included in the sale.
The same rule applies to the sycamore tree. Its method of cultivation was by cutting it down, after which it would grow back as a long, straight, and hard log, suitable to be used for beams - since long, straight wood is required for beams. "Besulas hashikmah" - a virgin sycamore is a sycamore that has never been cut down, and it is included in the sale. However, a non-virgin sycamore, which has already been cut down so that it grows straight and serves as beams - work has been invested in it, so it stands on its own and is not included in the sale of the rest of the field.
In summary: In this Mishnah we learned that one who sells a field without specifying, sells along with it everything that is secondary to it and serves its needs: stones designated for a fence, reeds set up to support vines, produce attached to the ground, a reed partition smaller than a beis rova, and a watchman's booth not made with plaster. In contrast, anything that stands on its own due to its size, permanence, or the work invested in it - is not included in the sale: a reed partition larger than a beis rova, a watchman's booth made with plaster, a grafted carob tree, and a non-virgin sycamore.