Peah 8:2-3

Peah 8:2

The needy are believed when they sell produce and tell the buyer that it is leket, shich’cha or peah when they sell these things in their proper season; they are believed about maaser ani (tithe for the poor) for the entire year. A Levite is always believed when he says that produce is maaser rishon (first tithe) from which terumas maaser (the kohein’s portion) has been separated. The needy are only believed when they report about things that people are in the habit of giving them.

Peah 8:3

For example, they are believed about wheat but not about flour or bread. They are believed about a stalk of grain but not about shucked kernels, either raw or cooked. They are believed about beans but not about bean paste, either raw or cooked. They are believed about oil if they say that it is made of maaser ani (tithe for the poor) but not if they say that it is made of deformed olives that the needy knock out of the trees (because oil of this kind is uncommon).