The snake refers to the rod of Moses, who showed the Pharoah of Egypt God's ability to turn a simple shepherd's staff into a serpent, and thus, that in order to heal his people from lives of death and misery, the Pharoah must let God's First Family, the Jews, go free to return to the land God promised them that is now known as Israel. I am not a member of the "First Family" which is the Jewish nation, but am a Christian that supports all that our faith is built upon--Christ's teachings and his word that essentially explained to the ordinary man on the street, all of God's goodness, His 10 commandments that he gave to Moses at Sinai Mountain, and That story is in the old Testament and was explained to me by medical professors who taught both medical and nursing skills, the Hippocratic Oath, which mentions to not do further harm to the patient, and other minutia of modern practices.