Jesus said: 'Goats on the left, sheep on the right' (Matthew 25:33).
Jesus also told Peter that if he wanted to catch fish do it from the right side of the boat. They did and filled the boat with fish.
John 21:6 (NIV) ... He said, "Throw your net on the right side of the boat and you will find some." When they did, they were unable to haul the net in because of the large number of fish."
Origin of Left & Right: Conservatives are called the "right" and Liberals are called the "left".