Demai, Chapter Two, Mishnah Three
In the previous mishnah we learned how a person becomes trustworthy such that others can buy his produce without fear that it has not been tithed. In todays mishnah we learn how someone can become a chaver. The word chaver which in modern Hebrew means either friend or associate refers to a person who is known to be extra cautious in matters of purity. He is one who eats his non-sanctified produce (hullin) while in a state of purity. The chaver is also trustworthy when it comes to matters of tithing. According to many scholars and traditional commentators there may be a connection between being a chaver and being a Pharisee, a Second Temple group whose members were also known for being meticulous in matters of purity.
1) One who takes upon himself to become a chaver may not sell to an am haaretz either moist or dry [produce], nor may he buy from him moist [produce], nor may he be the guest of an am haaretz, nor may he host an am haaretz as a guest while [the am haaretz] is wearing his own garment.
2) Rabbi Judah says: he may not also raise small animals, nor may make a lot of vows or merriment, nor may he defile himself by contact with the dead. Rather he should be an attendant at the house of study.
3) They said to him: these [requirements] do not come within the general rule [of being a chaver].
Section one: An am haaretz is by definition not cautious in matters of purity and can be assumed to be impure. Therefore, a person who wishes to be a chaver should not sell his produce to an am haaretz. The mishnah rules that this is so for moist produce, which is susceptible to impurity and for dry produce as well, even though it is not susceptible to impurities, until it becomes wet. The fear is that the later on the dry produce will come into contact with a liquid and the am haaretz will then make it impure.
Just as the chaver cannot sell to an am haaretz, he cannot buy from him. However, this only applies to moist produce because if the produce is still dry then it cannot have become impure.
The chaver cannot be a guest at an am haaretzs home because the am haaretz doesnt observe the purity regulations, nor does he tithe.
The chaver cannot host the am haaretz while the am haaretz is wearing his own clothing. The problem is that the clothing transmits a high level of impurity even without coming into direct contact. Therefore, the chaver would have great trouble in avoiding the impurity of the am haaretz. However, if the am haaretz was wearing the chavers clothing (which does not make the clothing impure) the chaver can avoid direct physical contact with the impure am haaretz.
Section two: Rabbi Judah adds several stringencies to the list of what one needs to do to be accepted as a chaver. The first is that he is not allowed to raise small animals (sheep and goats) in the land of Israel because they destroy the crops (see Bava Kamma 7:7). The second is that he wont take many vows. A person who takes many vows is considered rash and not trustworthy. Third, he wont engage in much laughter or merriment. Laughter and merriment in rabbinic literature often has a connotation of licentiousness. Finally, what he will do is sit in the Bet Midrash, the study house, and learn Torah. In other words, to Rabbi Judah, being a chaver is practically synonymous with being a sage.
Section three: The other sages disagree with Rabbi Judah and limit the concept of chaver to matters connected with the purity laws. A chaver is one who is scrupulous specifically in matters of purity. While being a sage is obviously a great merit, one does not have to be a sage, or scrupulous in matters of vows, raising animals etc, in order to be a chaver. All one has to do is carefully observe the purity laws.