(Mishnah): Amei Ha'aretz (ignorant people) are believed for Leket, Shichechah and Peah during their harvest season (because Leket etc. is common) and on Maaser Ani throughout its year. A Levite Am Haaretz is always believed, but only about something that men are accustomed to give them.

(Gemara) Question: Until how far away from the field are they believed because of the reason that Leket etc. is still common?

(R. Chanina): Anywhere to which they walk and return the same day. It once happened that Rebbi believed five (poor) brothers that they had collected five Kur of wheat (of gifts to the poor). Could they have received so much (from one person)? It was actually a combination of gifts that they received from several people that added up to a Kur (each).

Question (R. Elazar of Rome to R. Yosi): Does the Mishnah follow the view of R. Eliezer (and not the Chachamim)? R. Eliezer said that if an Am Ha'Aretz was seen separating Maaser Sheni, he is believed to have separated Maaser Rishon. (The Chachamim argue that he is not believed over Maaser Rishon.)

Answer (R. Yosi): It follows all opinions - as a person does not do a Mitzvah (give Maaser Ani to the poor) in a matter of sin (giving him Tevel - untithed produce that he will eat).

(R. Elazar citing R. Hoshiya): Just as Jews are not suspected of not separating Terumah Gedolah (where if it was not separated, eating the produce is punishable by death), so too a Levite is not suspected for Terumas Maaser (the 1/10th separated from the Levi's Maaser Rishon and given to the Kohen).

(R. Hoshiya): Our Mishnah also teaches this - 'a Levite is always believed'.

Question (R. Mana): Is a Levi always believed, even in Sheviis (to say that it is Maaser from the sixth year and does not have the sanctity of Sheviis produce)?

(R. Bun bar Chiya): A Levi is believed that something is certain Maaser Rishon, to exempt it from Maaser Sheni; but if the Levi says, "I was given (this Maaser Rishon)" or "This is my own produce", they are not believed to exempt it from Maaser.

(Our Mishnah): They are only believed about something that it is the way of people to give them.

The correct reading of the Mishnah is 'they are only believed about the (type of thing) that people are accustomed to give them'.

(Mishnah): The poor are believed about wheat but not about flour or bread. They are believed about rice in its stalk but not when it is raw or cooked.

They are believed about beans but not when they are pounded, whether raw or cooked. They are believed about oil to say that it is Maaser Ani but not that it comes from Nikuf olives. They are believed about a raw vegetable but not a cooked one (as people do not usually give in the form of cooked food), unless it is a small amount, as it's normal for the landowner to give from his bowl.

(Gemara) Question: Is the Levi believed to say, "I was given wheat and I made it into flour" or "I was given wheat and I made it into bread"?

Answer: He is certainly believed.

Even if everyone knew that the poor collected on this day, he is still not believed (to say 'I received flour that was ground by the owner').

Baraisa (R. Yehuda): In a place where the owner is accustomed to crush the Olelos grapes for the poor, the poor man is believed to say, "This wine is of Olelos". Similarly, in a place where the owner is accustomed to pick Nikuf olives for them, the poor man is believed to say, "This oil is from Nikuf olives".

They forgot to separate Maaser Ani from a tree of Beis Asi, and they gave it straight from the pan in which they were cooked. (This supports the statement at the end of the Mishnah that it's normal for the landowner to give from his bowl.)