Gemara

65a: Reuven owned an inner house and an outer house. If he sold or gave (at the same time) the inner house to Shimon and the outer house to Levi, neither has rights to walk through the other, and all the more so if he gave the outer house and sold the inner house. (Since he gave the gift to Levi, this shows that he favors him.)

Suggestion: Also if he gave the inner house and sold the outer house, neither has rights to walk through the other.

Rejection (Mishnah): This applies to a sale, but one who gives (a gift) gives everything.

This shows that one gives generously. Also regarding the houses, Reuven gives generously to Shimon, and included a path.

71a (Mishnah - R. Akiva): (If one sells a field,) he keeps the pit, winery or dovecote, whether these are barren or full. He must buy a path to them;

Chachamim say, he need not buy a path;

This refers to one who sells, but one who gives a gift gives all of them. If one is Makdish a field (gives it to Hekdesh), they all become Hekdesh;

R. Shimon says, (of all the things that would not be included in a sale,) only grafted carob trees and sycamore stumps are Hekdesh.

(Rav Huna): Even though if Reuven buys two trees in Shimon's property, he does not acquire land with them (between or around them, or the right to plant others if these will die or dry up), if Reuven sold his property and kept two trees for himself, he keeps land with them.

Even R. Akiva says that one sells generously only regarding pits and cisterns, which endure. Trees weaken. If he would not retain land, the buyer could tell him 'uproot your trees and leave' (when they dry up).

Question: In a Beraisa, R. Shimon explains that one is Makdish carob and sycamore with a field, lest they nurture from the surrounding Hekdesh land. If one leaves land for his trees, they nurture from his own property!

Answer: R. Shimon holds like R. Akiva (that one sells, and is Makdish, generously). Rav Huna's law is like Chachamim (one sells stingily).

72b: R. Shimon addresses Chachamim according to their reasoning. I (R. Shimon) say that just like one sells stingily, he is Makdish stingily, and keeps land for himself. You may say that he is Makdish more generously than he sells, but admit that he (is stingier than one who gives. He) is Makdish only grafted carob trees and sycamore stumps (lest they nurture from Hekdesh, but not pits...)

Chachamim hold that he is Makdish as generously as he gives.

Rishonim

The Rif and Rosh (35a and 4:9) brings the Gemara on 65a.

Rif and Rosh (38a and 4:17): The Halachah follows R. Akiva, that one sells generously.

Rambam (Hilchos Mechirah 25:4): If Reuven owned an inner house and an outer house, and he sold or gave both of them to different people, neither has rights to walk through the other, and all the more so if he gave the outer house and sold the inner house. If he gave the inner house to Levi and sold the outer house, Levi has rights to walk through the outer house, for one gives more generously than he sells.

Magid Mishneh: The Ri mi'Gash says that this is when he was Makneh (transferred ownership) of them at once. If he sold the inner house, and afterwards sold the outer house, the first recipient immediately acquired a path, for we hold like R. Akiva, that one sells generously, and one who buys a pit gets a path to it. Similarly, if first he sold the outer house, and then gave the inner house, the latter recipient did not acquire a path, for the owner did not keep one for himself. We rule like R. Akiva, that one who keeps a pit must buy a path to it.

Rosh (4:17): The Halachah follows R. Akiva, that one sells generously.

Poskim

Shulchan Aruch (CM 214:9): If Reuven owned an inner house and an outer house, and he sold or gave both of them to different people, neither has rights to walk through the other, and all the more so if he gave the outer house and sold the inner house

Beis Yosef (DH Mi): When he sold or gave both, surely he was not generous to one and stringy to the other. Rather, he gave the entire outer house to one, and the entire inner house to the other.

SMA (37,38): The only exit of the inner house is through the outer. He gave also to Shimon generously, that no one has rights to pass through. Levi must appease Shimon, so he will allow him to pass through.

Gra (39): Even though we hold like R. Akiva, that one sells generously, and Chachamim hold that one one gives stingily, one gives more generously than he sells.

Mabit (2:65): A case occurred in which Reuven gave to his wife, for Tosefes Kesuvah, the house in which he lived and the house under it and the pit in front of it and the pantry. Before his death, he wrote to his relative the middle house between the two Aliyos, and he also wrote to his wife what he already wrote in the Kesuvah. The relative's house was between the wife's house and another house on the north. A Chatzer separated this house from the wife's house, in which were the pit, pantry, oven and a Beis ha'Kisei. The relative wanted rights to pass through the Chatzer, and rights to also use the oven and Beis ha'Kisei, which werd not mentioned in the gift to the wife. The wife says that the pantry is in the east, and the opening of her house is in the middle, so she received it all. Also, the main opening of the relative's house opens to another Chatzer, so she does get rights to pass through this Chatzer. I say that the relative would have no rights to pass through even if she had no other opening, like one who received an inner house. The Chatzer was included in what he wrote to his wife, for it is called 'Dirah (dwelling)'. Even a city is called Dirah! When he wrote to his wife, he did not mention the oven and Beis ha'Kisei, for they are Tefel to (secondary to and included with) the Chatzer, which is included with the house. The relative would not have rights to pass even if the gifts came together, and all the more so in this case, when the other house was already written to the wife in her Kesuvah. The relative gets an opening through the other Chatzer, which was not given at all, and was left for the husband's heir. Also the lower house that the wife received was given with a path.

Shulchan Aruch (ibid): If he gave the inner house to Levi and sold the outer house to Shimon, Levi has rights to walk through the outer house, for one gives more generously than he sells.

SMA (39): Since he gave a gift to Shimon, surely he loves him more, and gave to him the best rights.

Shulchan Aruch (10): This is when he was Makneh of them at once. If he sold or gave the inner house to Levi, and afterwards sold or gave the outer house to Shimon, Levi immediately acquired a path, and he does not lose this afterwards. Similarly, if first he sold the outer house to Shimon, and then gave the inner house to Levi, Levi did not acquire a path.

Gra (40): We hold that one sells all rights that he has (Bava Kama 8b).

Prishah (16 DH u'Mah): This is only when the original owner said only that he gives or sells the inner house (and automatically, he keeps the outer house). If he explicitly mentioned that he keeps the outer house, he did not give a path.