Today it seems perfectly natural for us to shake hands when we greet someone or say goodbye. But like so many things that we do without thinking such actions at one time probably represented something. For example, in primitive  life the hand was used to fight enemies, kill animals, and make spears and tools. So when the hand was extended to someone, it showed that the person was not armed or ready for fight. We know that the hand was an important symbol in early religion, probably as a mark of power. The Greeks prayed to their gods with raised hands. Presenting the hands palm to palm was at one time the way an inferior  person paid respect to a superior  one. Among the Arabs, it was customary at one time to kiss the hand of a superior. Later on, polite Arabs began to resist the efforts of people to kiss their hands, and sometimes they would end up shaking hands as each tried to prevent the other from showing this mark of "inferiority ." The early Greeks held out the right hand when they wished to show friendship to a stranger. So we can see that the hand, and what was done with it, was full of meaning to people down through the ages. And while we shake hands without thinking, we are really carrying on a custom that has been  _ to us from ancient times. The phrase " hand down" in the last sentence means   _  .
put down leave down give down pass down