Related for Demai 2:3
הַמְקַבֵּל עָלָיו לִהְיוֹת חָבֵר, אֵינוֹ מוֹכֵר לְעַם הָאָרֶץ לַח וְיָבֵשׁ, וְאֵינוֹ לוֹקֵחַ מִמֶּנּוּ לַח, וְאֵינוֹ מִתְאָרֵח אֵצֶל עַם הָאָרֶץ, וְלֹא מְאָרְחוֹ אֶצְלוֹ בִּכְסוּתוֹ. רַבִּי יְהוּדָה אוֹמֵר, אַף לֹא יְגַדֵּל בְּהֵמָה דַקָּה, וְלֹא יְהֵא פָרוּץ בִּנְדָרִים וּבִשְׂחוֹק, וְלֹא יְהֵא מִטַּמֵּא לְמֵתִים, וּמְשַׁמֵּשׁ בְּבֵית הַמִּדְרָשׁ. אָמְרוּ לוֹ, לֹא בָאוּ אֵלּוּ לַכְּלָל:
One who takes it upon himself to be a <i>Chaver</i> [one who scrupulously observes tithes and purity laws] may not sell to an ignorant person wet or dry [produce], nor buy from him wet [produce], nor be the guest of an <i>Am HaAretz</i> nor host him as a guest [when he is clothed] in his [own] garments. Rabbi Yehudah says, “He may not even raise small animals, nor be unrestrained regarding vows and entertainment, nor become defiled by [contact with] a corpse, and frequent the house of study.” They said to him, “These are not included in the general principle.”