Bava Basra, Chapter 6, Mishnah 6. The Mishnah before us presents a situation where Reuven has a garden, and inside his garden is another garden belonging to Shimon. In order to access his garden and cultivate his vegetables, Shimon must pass through Reuven's property. The two indeed reached an agreement guaranteeing Shimon the right of way, but they did not specify its exact scope; all that is known is that Shimon is allowed to pass through Reuven's garden to reach his own.
There are two possibilities before us:
Possibility A: The path that Shimon is allowed to use goes through the middle of Reuven's garden.
Possibility B: The path is located at the side of the garden.
The practical difference between them is this: We cannot expect Reuven to divide his planting into two separate plots. Therefore, when the path goes through the middle, Reuven is allowed to plant his cabbages throughout the entire area of the garden, including the location of the path, and Shimon must walk around the cabbages as he goes. In contrast, when the path is located at the side of the garden, Reuven has no need to plant there, since it is easy for him to stop his planting right next to the path; thus, the path will remain clear, without obstacles that could trip Shimon up and cause damage.
Hence the question: What exact rights of passage are granted to Shimon when nothing was specified in the terms of the agreement other than the location of the path?
The Mishnah begins: "Mi sheyeish lo ginah lifnim miginaso shel chaveiro" - Someone who has a garden inside his fellow's garden. This is Shimon, whose garden is located within the borders of Reuven's garden.
When the path goes through the middle of the garden:
"Nichnas bsha'ah shederech bnei adam nichnasin, veyotzei bsha'ah shederech bnei adam yotzain" - He enters at the time when people normally enter, and leaves at the time when people normally leave. Shimon is allowed to access his garden, but only during the standard hours for garden work, meaning daytime. He is not allowed to stay there at night, nor wander around whenever he pleases. His access is limited, but it is sufficient to allow him everything needed for his garden.
"Ve'eino machnis lesochah tagarin" - And he may not bring merchants into it. Shimon does not have the right to bring other people with him. If he is growing carrots in his garden and finds a buyer for his produce, he may not bring the buyer with him, as this would mean two people walking on the narrow path, causing a lot of damage to the path and even to the cabbages that Reuven wants to grow.
"Velo yikanes misochah lesoch derech acher" - And he may not enter from it into another path. Shimon's complete right to use the path is solely for the purpose of entering his garden, and this is his only right. He may not use the path as a shortcut to reach another destination, such as Levi's courtyard.
"Vehachitzon zorea es haderech" - And the outer one may plant on the path. The owner of the outer field, Reuven, who owns the land where the path passes, is allowed to plant his vegetables even on the path itself and grow his cabbages there as he needs, since it is his property and there is no reason to force him to suffer inconvenience. Shimon, however, is required to walk around the cabbages and not damage them.
When the path was given at the side:
Everything stated so far applies to a path going through the middle of Reuven's field or garden. However, in a case where "nasan lo derech min hatzad mida'as sheneihem" - he gave him a path at the side with the consent of both of them. Meaning, they mutually agreed that Shimon's access path would be at the side of Reuven's property and not in the middle (and they are not obligated to agree to this, but they both did agree). The law is more lenient here, because we do not expect Reuven to plant there, nor is he required to do so; it is easy for him to stop his planting a bit earlier, and the path will remain open and more convenient for Shimon.
"Nichnas bsha'ah shehu rotzeh veyotzei bsha'ah shehu rotzeh" - He enters at whatever time he wants and leaves at whatever time he wants. Shimon is allowed to walk on the side path whenever he pleases, because Reuven cannot claim that he is disturbing him, and his passage does not disturb anyone.
"Umachnis lesochah tagarin" - And he may bring merchants into it. Since Reuven is not growing cabbages on this path, Shimon is allowed to bring along a buyer who wants to purchase his carrots, and both of them can walk together on the path, because this does not cause any disturbance or damage to Reuven.
"Velo yikanes misochah lesoch sadeh acheres" - And he may not enter from it into another field. Even though Shimon is allowed to use the path to enter his garden at any time, he may not use it as an access route for other purposes. In Reuven's words: You are permitted to pass through my garden to reach your garden, but not to reach another destination.
"Vezeh vezeh einam rasha'im lezor'ah" - And both of them are not permitted to plant it. Neither Reuven nor Shimon is allowed to plant anything on the side path. Its purpose is solely for accessing Shimon's garden: Reuven has no need to plant there, since his planting would obstruct the path, and Shimon has no right to plant there at all.
In summary: In this Mishnah, we learned that the scope of the right of way is determined by the location of the path. A path that goes through the middle of the garden grants Shimon limited access: only during standard hours, without bringing in merchants, and without passing through to another destination, and the owner of the property is allowed to plant even on the path itself. In contrast, a path given at the side with the mutual consent of both parties grants entry and exit at all times and the right to bring in merchants, but it too does not permit passing through to another field, and neither of them is allowed to plant on it.