Explanation: This is R. Tam's text. "Mar" means in place of [lard of] the innards, like b'Mar d'Shechutah in Chulin (94a), and like b'Mar d'Parzela (in lieu of copper - Bava Kama 113b).

Inference (R. Tam): Wherever it mentions Ma'aser regarding Shevi'is, it discusses one who gives [or sells] Ma'aser Sheni in the guise of Chulin, e.g. "they are in their Chazakah for Ma'aser and Shevi'is" (Gitin 61b), and likewise "he is not concerned for spices in it, not for Shevi'is and not for Ma'aser", in Chulin (6a).

Support: The wording "Ma'aser" proves like this, for when the concern is that [Peros] were not tithed, it mentions Tevel or Demai.

Explanation: It connotes to [the Makshan] that [the law] itself is not needed. It is obvious that one who is trusted about Taharos is trusted about Shemitah, since he conducts like very pious people who eat Chulin in Taharah. (It was taught for the inference.)

Inference: "He is careful about Shemitah" connotes that a Stam Am ha'Aretz is suspected about Shemitah, just like about Taharos.

Question #1: In Gitin (61a), it says "what is the difference between the Reisha and Seifa, that it is lenient about an Am ha'Aretz' wife, and stringent about one who is suspected about Shemitah?";

And Rava said "here we discuss an Am ha'Aretz of R. Meir, and Tum'ah and Taharah of Rabanan. Since it taught regarding Tum'ah and Taharah an Am ha'Aretz Stam, and regarding Shemitah it says "who is suspected", this connotes that Stam Amei ha'Aretz are suspected about Taharos, but not about Shemitah!

Implied suggestion: We can infer also from the Heter to select and grind with an Am ha'Aretz suspected about Tum'ah and Taharah, and we do not forbid due to Shevi'is (that a Stam Am ha'Aretz is not suspected about Shemitah)!

Rejection: We cannot infer anything from this! Perhaps it discusses other years of the Shemitah cycle (when there is no concern for Peros Shemitah), and not in Shemitah, or Peros known that they are not of Shemitah.

Support: Similarly, it discusses Peros known that they were tithed according to Rava, who argues with Abaye's answer that most Amei ha'Aretz tithe.

Question #2: From here is difficult for R. Tam, who explains in Kesuvos (24a) regarding "my Peros are Chadash, and my friend's are Yashan", that a Stam Am ha'Aretz, even though he is suspected about Demai, is not suspected about Shemitah;

He contradicts the Rashbam, who explains that it mentions Chadash and Yashan due to Shemitah, and when [Abaye] answers that most Amei ha'Aretz tithe, i.e. and the same applies to to Shemitah (they properly observe it). R. Tam asked several questions against the Rashbam, like he explained in Kesuvos;

R. Tam explains that [he said] Chadash and Yashan to praise [the Peros] he sells, and not regarding Isur v'Heter.

Consequence: Now (according to R. Tam), according to R. Ila'a, one who is suspected about Taharos [which is] mid'Rabanan, he is suspected about Shemitah, all the more so Stam Amei ha'Aretz, just like they are suspected about Demai mid'Oraisa, they are suspected also about Shemitah.

Poor Answer: It is difficult to establish a Stam Am ha'Aretz everywhere, who is not suspected about Shemitah, to be when we saw him observe it covertly in his house.

Question #3: A Mishnah in Demai (3:4), and it is brought in Gitin (61b), says that one who brings wheat to a Kusi grinder or an Am ha'Aretz grinder, he is not concerned for Ma'aser, and not for Shemitah;

Inference: Stam Amei ha'Aretz are suspected about Shemitah!

Answer #1: It mentioned Shemitah due to a Kusi.

Answer #2: It discusses an Am ha'Aretz who is known to be suspected.

Also [we establish like this] the case of one who buys a Lulav from his friend in Shemitah. It says about this in Sukah (39a) that we do not give money of Peros Shemitah to an Am ha'Aretz.

Also what is brought in Chulin (6a), one who gives to his neighbor a dough to bake or a pot to cook, he need not be concerned for Se'or and spices in it, not for Shemitah or Ma'aser. And if he said "make for me from yours", he must be concerned... all these discuss one who is Vadai suspected.

Question: How is it proven from this in Chulin that they decreed about a mixture of Demai? Perhaps one who is suspected is worse than a Stam Am ha'Aretz regarding Ma'aser Rishon, like is proven in Gitin (61a) according to Abaye?

Answer: He asks properly according to Rava, who holds that [one who is suspected] is not more stringent [than a Stam Amei ha'Aretz].

Explanation: Therefore [one who is suspected about Shemitah, all the more so] he is suspected about Ma'aser.

Question: In Shabbos (17b) we say that regarding Terumah, since it is possible to do like Shmuel, that one wheat [kernel] exempts the [entire] stack, they are not suspected;

Also here, we should not suspect him about Ma'aser Sheni, since it is possible to do like Shmuel, that Hekdesh worth a Maneh (or any amount) that he redeemed it on a Perutah, it is redeemed, and the same applies to Ma'aser Sheni!

The She'altos of Rav Achai says explicitly about Kerem Revai that one may redeem it on a small amount, and Ma'aser Sheni and Kerem Revai have the same law everywhere, for we learn them from each other from a Gezeirah Shavah "Kodesh-Kodesh", like it says in Kidushin (54b)!

And presumably, it is permitted even l'Chatchilah, just like Hekdesh, in Erchin (29a) which is permitted [to redeem on a Perutah] nowadays, regarding the man who made his property Cherem!

Implied question: In Gitin (65a), we establish [the Mishnah about] how do we scheme about Ma'aser Sheni [to redeem it without adding a Chomesh, i.e. he gives money to his child, or male or female Eved Ivri, and the latter redeems it] to discuss Ma'aser nowadays, which is mid'Rabanan;

It could have asked that nowadays, what scheme is needed to exempt from a Chomesh? He can redeem a Maneh on a Perutah!

Answer: We rejected it through another question - nowadays there is no Amah Ivriyah (for there is no Yovel).

Strengthening of question: Cases occur constantly, and we redeem Kerem Revai worth a Maneh on a Perutah!

Answer: Ma'aser is unlike Terumah. Sometimes one does not have a Perutah available to redeem it. Also, sometimes one has only a little Ma'aser compared to a Perutah, and he does not want to give a Perutah corresponding to it.

Observation: According to R. Ila'i above (30a), that one who is suspected about Taharos is suspected about Shemitah, except for when we saw him observe [Shemitah] covertly, what it says here that he is suspected only about that matter, this is not precise. Rather, it is for that matter and everything similar;

He comes only to exclude [that he is not suspected about] the entire Torah.

Explanation: [His father disgraced our Talmidim] about Taharos, like his son did.