Simmer a meaty ham bone with 2 lbs. marrow beans in 4 quarts water for 2 1/2 hours. Cut up 5 stalks celery, 1 potato, 8 carrots, 1 green pepper and 2 onions; add to soup with 1 can tomatoes, oregano and salt and pepper to taste. Simmer 40 minutes longer. Remove meat from bone, add to soup and serve.