Gemara

68b (Mishnah): If one sells a field, this includes rocks needed for the field, sticks needed for a vineyard, Chitzas ha'Kanim (a cluster of sticks) less than Beis Rova (the amount of land in which a quarter of a Kav of seed is sown);

It does not include rocks and sticks not needed for the field. If he said 'it and everything inside', all these are included. In any case, he did not sell Chitzas ha'Kanim that is Beis Rova.

Question: Which rocks are needed for the field?

Answer #1 (Chachamim of Bavel): They are rocks that hold down sheaves left to dry so they will not be blown away.

(R. Meir considers more things to be needs of a vineyard than Chachamim do (78b).) R. Meir includes rocks prepared for this, even if Lo Machtan (they are not placed). Chachamim include them only if Machtan.

Answer #2 (Ula): They are rocks arranged like a wall around the field.

R. Meir includes them if they are prepared, even if they are not arranged. Chachamim include them only if they are arranged.

(D'Vei R. Yanai): Sticks needed for a vineyard are to support vines.

R. Meir includes if they are smoothed out, even if they are not inserted in the ground. Chachamim include them only if they are inserted.

(Mishnah): Chitzas ha'Kanim that is less than Beis Rova (is sold).

This is even if they are strong.

(Mishnah): It does not include rocks not needed for the field.

R. Meir excludes rocks that were not prepared. Chachamim exclude rocks (even if they were prepared) if Lo Machtan.

Ula says that the rocks are for a wall. R. Meir excludes them if they are not prepared. Chachamim exclude them if they are not arranged.

(Mishnah): Nor sticks not needed for a vineyard.

R. Meir excludes them if they are not smoothed out. Chachamim exclude them if they are not inserted in the ground.

(Mishnah): Chitzas ha'Kanim that is Beis Rova is not sold.

This is even if the sticks are small.

(R. Chiya bar Aba): Not only clusters of sticks, but even a small spice patch, if it is called by its own name, is not included.

(Rav Papa): This is only if it is called 'Ploni's spice-patch'.

78b (Abaye): The following Tana'im all say that when one sells something, he includes everything used with it: R. Eliezer, R. Shimon ben Gamliel, R. Meir, R. Noson, Sumchus, and Nachum ha'Midi.

(Beraisa - R. Meir): If one sells a vineyard, everything needed for it is included.

Rishonim

The Rif's text of the Mishnah said Mechitzas ha'Kanim. (Usually, 'Mechitzah' is a wall.)

SMA (CM 215:30): Also Mechitzas ha'Kanim is like the Rashbam explained Chitzas ha'Kanim (a cluster of sticks).

Rif and Rosh (40a and 5:8): Several Tana'im say that one who sells something includes everything used with it. They are a Shitah. The Halachah does not follow any of them.

Nimukei Yosef (36b DH v'Lo Es ha'Kanim): Even if the sticks were fixed to support vines, since they were not put under the vines, they are not Batel to the vineyard.

Rambam (Hilchos Mechirah 26:2): One who sells a field includes rocks arranged for a fence, and rocks resting on sheaves, for they are needed for the field.

Magid Mishneh: The Rambam rules like Ula and Chachamei Bavel. Both of their answers are true; they do not argue.

Rambam (ibid): He sold the smooth sticks placed under vines to hold up the vineyard, for they are needed for it. He sold Mechitzas ha'Kanim less than Beis Rova, even if the sticks are thick and strong. He did not sell rocks not arranged for a fence, and rocks not resting on sheaves, even if they were prepared for this. He did not sell sticks not under vines, even if they are smooth and prepared for this. It does not include rocks and sticks not needed for the field. If he said 'it and everything inside', all these are included.

Rambam (3): In any case, he did not sell Mechitzas ha'Kanim that is Beis Rova, even if the sticks are thin and small. He did not sell a small spice patch, if it is called by its own name, e.g. it is called 'Ploni's spice-patch.'

Magid Mishneh: The Rashbam explains that these are like independent fields. This is like one who had a field in between two fields. If he sold the two and everything in them, he did not sell the middle field.

Rosh (Teshuvah 75:3): A case occurred in which parts of Reuven's house fell. He did not rebuild the fallen rocks and beams. He gave half his house to his daughters, and the other half and his Metaltelim to his wife. The rocks and beams are considered like the house. Since they are in his Reshus and he did not sell them, this shows that he planned to rebuild them if he will have the opportunity. This is like we say in Bava Basra, that one who sells a field sells the rocks and sticks needed for it. All the more so, one who gives a house includes the rocks and sticks needed for it, for people give more generously than they sell.

Tosfos (69a DH v'Hu): It is unreasonable to require that the rocks are now on the sheaves, since the sheaves themselves are Metaltelim and they are not sold! Rather, they are included if they were once on the sheaves.

Tosfos (69a DH Mechulakim): 'Smooth' means that the outer layer was peeled off, so they will not get wormy.

Poskim

Shulchan Aruch (CM 215:5): One who sells a field includes rocks arranged for a fence or resting on sheaves, for they are needed for the field.

Beis Yosef (DH u'Mah she'Chosav v'Es): The Rashbam explains that even though the rocks are used for a non-stationary usage, since they never leave the field, they are considered to be attached.

Beis Yosef (DH v'Chosav): The Tur says that only rocks on sheaves are sold. He holds that Ula holds that rocks arranged for a fence are sold, and all the more so rocks on sheaves. Chachamei Bavel hold that rocks on sheaves are sold, but not rocks arranged for a fence. He rules like the more lenient opinion, for ha'Motzi mi'Chavero Alav ha'Re'ayah.

Bach (DH u'Mah she'Chosav v'Hu): The Rashbam explains that rocks in the field are included, even if they were never on the sheaves.

Gra (10): We rule like Chachamim against an individual. Also, we established R. Meir to be part of a Shitah.

Shulchan Aruch (ibid): He sold the smooth sticks placed under vines to hold them up.

SMA (29): The Tur requires that they were once put under the vine, for designation is not significant.

Shulchan Aruch (ibid): He sold Mechitzas ha'Kanim less than Beis Rova, even if the sticks are thick and strong. He did not sell rocks not arranged for a fence, and rocks not resting on sheaves, even if they were prepared for this.

Rema: Some say that if the rocks were once on the sheaves, they are sold.

Beis Yosef (DH u'Mah she'Chosav Rabeinu): The Tur says that the rocks were placed once on the sheaves, so they will not blow away. This is like Tosfos. The Rambam connotes that they are now on the sheaves.

Shulchan Aruch (ibid): He did not sell sticks not under vines, even if they are smooth and prepared for this. If he said 'it and everything inside', all these are included. In any case, he did not sell Mechitzas ha'Kanim that is Beis Rova, even if the sticks are thin and small. He did not sell a small spice patch, if it is called by its own name, e.g. it is called 'Ploni's spice-patch.'

Beis Yosef (DH Lo Es Chitzas): He did not sell a patch even if it is less than Beis Rova, if it is called by its own name. The Gemara mentioned a spice-patch, for it typically has a name. The Shi'ur applies only to Chitzas ha'Kanim, for it has a name only if it is Beis Rova.