GOOD AND EVIL KIDNEYS
According to the Talmud, "Our Rabbis taught: Man has two kidneys, one of which prompts him to good, the other to evil; and it is natural to suppose that the good one is on his right side and the bad one on his left, as it is written, ’A wise man’s understanding is at his right hand, but a fool’s understanding is at his left.’" Berakoth, 61a