Cover beans with water in large pot or soup kettle and soak overnight. Rinse beans well and return to pot with ham bone and 3 litre of water. Simmer, uncovered, for 2 hours. Add parsley, onions, garlic, celery and tops, salt and pepper. Simmer, uncovered, for 1 hour or until vegetables are tender. Remove ham bone, dice the meat, and add meat to soup. Serve hot.