A city whose roofs constitute its wall, or one that was not surrounded by a wall from the time of Joshua the son of Nun, is not [treated] according to [the law of] the houses of walled cities. These are the houses of walled cities: Three courtyards consisting of two houses each, surrounded by a wall since the days of Joshua the son of Nun; for example, Old Katzra of Tzipporim, Chakra of Gush Chalav, Old Yodphas, Gamla, Gedod, Chadid, Ono, and Jerusalem; and the same for all that are like them.