Question (Rami bar Chama - Mishnah): If one said 'these Peros are forbidden to me' or 'to my mouth', he may not benefit from Chilufeihem or Giduleihem.

If he forbade 'what I eat' or 'what I taste', he is permitted Chilufeihem and Giduleihem;

This applies to a species in which the seed disintegrates. If not, even Gidulei Giduleihem are forbidden. (Additional growth is not Mevatel the bulb!)

Answer (R. Aba): Vows are different. Since he can permit his vow, it is like a Davar she'Yesh Lo Matirin, which is not Batel in a majority of Heter.

Question: One can permit a declaration of Terumah, yet it can be Batel!

(Mishnah): If one Se'ah of Tamei Terumah fell into less than 100 Sa'im of Chulin, it must all rot.

Inference: Had it fallen into 100 Sa'im, the Terumah would be Batel!

Answer #1: The case is, the Terumah was given to a Kohen, so the Yisrael may no longer permit his declaration of Terumah.

Question (Seifa): If the Terumah is Tahor, the mixture may be sold to a Kohen. (This shows that it was in the hands of a Yisrael!)

Answer: The case is, it belonged to a Yisrael that inherited it from his mother's father, who was a Kohen.

Rejection (Seifa): The mixture may be sold to a Kohen except for the value of the Terumah. (This shows that the Yisrael was obligated to give the Terumah to a Kohen!)

Answer #2 (to Question (c)): Rather, vows are different, for R. Nasan taught that it is a Mitzvah to permit them (therefore, it is as if they were already permitted):

(R. Nasan): One who vows is like one who builds a Bamah (his own Mizbe'ach, when this is forbidden). One who fulfills the vow (does not permit it) is like one who offered a Korban on the Bamah.

There is no Mitzvah to permit a declaration of Terumah.

(R. Yochanan): If a Litra of onions were tithed and planted, when they grow, one tithes the entire amount.

Question (Rav Chisda): A Litra of the grown onions were already tithed and permitted. How can you consider them to be totally untithed?!

Answer (Rava): A Mishnah supports R. Yochanan!

(Mishnah): If onions (from before Shemitah) were in the ground in Shemitah, and rain fell on them and they sprouted:

If their leaves are black, they are (entirely) forbidden (like Shemitah produce). If the leaves turned green, they are permitted.

When the leaves are black, we do not say that what grew before Shemitah remains permitted!

Rejection (Rav Chisda): The Mishnah does not say that the entire onions are forbidden, only what grew in Shemitah!

Question: If so (Rosh - the Tana holds that there is Isur and Heter in the same plant), what is the (unique) Chidush of R. Shimon ben Gamliel?

(Beraisa - R. Shimon ben Gamliel): The amount that grew in a forbidden state (Shemitah) is forbidden; the amount that grew in a permitted state is permitted.

According to Rav Chisda, the first Tana (we mentioned, i.e. the Tana of our Mishnah) agrees!

Answer: R. Shimon ben Gamliel taught the entire Beraisa.

(Even though there is no proof for R. Yochanan, he is not refuted.) R. Shimon ben Gamliel taught [that the source is not Batel] only when he did not toil ( the onions grew by themselves);

When he toiled (e.g. in R. Yochanan's case, the owner toiled to plant the onions, so the initial bulb) is Batel once the added growth exceeds the initial size.

Question: Is it really true that whenever he toiled, what is planted is Batel when the added growth exceeds it?!

If a Litra of Ma'aser Rishon (from which Terumas Ma'aser was not taken) was planted (in Shemitah), he toiled; yet we learned that tithes must be removed on the initial Litra from other produce! (If it would be Batel, it would be like Shemitah produce, which is exempt from tithes!)

Answer: Ma'aser is different, for the Torah said "Tithe, tithe all produce of your seeds";

This refers to a normal case, in which one planted Heter. (It was already tithed, and the Torah obligates tithing it again.) People do not normally plant Isur. (If one did, it is not Batel the Isur remains.