In Greek superstition if you have an itchy hand it foretells that you are either going to receive or give money.

If you're right hand is itchy it indicates that you will get money.  If you're left hand is itchy it indicates that you will give money.  If both hands are itchy then you will both give and receive money.

In general the right hand is considered to be luckier then the left hand.  For this reason it said that you receive from the right and give from the left.

Your hand is said to be "itchy" as it anticipates the transaction that is to occur.  In such your hand is said to prophesize the giving or taking of money.

Further the right hand is thought to be holy and the left unholy.  This is why you receive from the right, as in the case of money it is usually believed better to give then receive.  

The use of the "right' can be further be seen in the Orthodox church, the Son of God sits to the right of the father, Orthodox leity cross with the right, etc.