Given that virtually no peasants would be literate and what writings they did make were not likely to be preserved, what primary sources do we have regarding their experience? Are they largely in the form of interviews/records created by literate clergy? Particularly interested in Russian peasants under the tsars and emperors and their relationship with the ruling classes (I'm familiar with the Primary Chronicle which touches on that under the princes, but obviously isn't the work of a peasant), but any answers are helpful!
One of the main sources would probably be judicial court records. While they may be in some ways a skewed, because they would solely be sources about peasants that came into contact with the judicial system, they would nevertheless be one of the only sources where we would be able to get more indepth insight into what they thought and perceived.
A now classic example is Carlo Ginzburgs work The Cheese and the Worms (1976), about the trial of an Italian miller with a very peculiar worldview, which we would never have known about if it wasn't for the fact that he was on trial for heresy.
While that is a more extreme example, lesser spectacular cases, like about drunken brawls, territorial disputes, inheritance cases and so on and so forth, would probably bring even better insight into the daily life and thoughts of peasants from direct witness testimonials.