One who accepts upon himself to be a chaver does not sell to an am haaretz wet or dry [food], does not buy from him wet [food], is not hosted by an am haaretz, and does not host him in his clothes. R’ Yehudah says: Also, he should not raise small domesticated animals, he should not overindulge in vows and frivolity, he should not render himself tamei [through contact] with dead bodies, and he should serve in the House of Study. They said to him: These things are not included.