Musar zu Kohelet 2:14

Therefore he whose eyes are on his head (Kohelet 2:14), should be more watchful to scrutinize the deeds of someone who he wishes to acquire as a friend, advisor, or workers over his household than he is watchful to scrutinize his food and drink. For his food and drink can only damage his body while his friends and workers can destroy his soul, belongings and all of his honor. King David peace be unto him said: "He will not dwell within my house, he who practices deceit. He who follows the way of the innocent, he will serve me" (Tehilim 101:6-7).