Arakhin 32B

אמר אביי: הכי קאמר ⁠— עד גמלא בגליל, עד גדוד בעבר הירדן, וחדיד ואונו וירושלים ביהודה.

Abaye said: This is what the baraita is saying: Until Gamla in the Galilee, i.e., all towns in the Galilee from Gamla southward were surrounded by a wall from the era of Joshua, son of Nun; and likewise, all towns until Gedod in Transjordan, which is the easternmost city, were surrounded by a wall; and Ḥadid and Ono and Jerusalem in Judea were surrounded by a wall from the era of Joshua, son of Nun.

רבא אמר: גמלא בגליל, לאפוקי גמלא דשאר ארצות; גדוד בעבר הירדן, לאפוקי גדוד דשאר ארצות; אינך דלא איכא דכותייהו ⁠— לא איצטריך ליה.

Rava said a different explanation: The baraita is elucidating the Mishnah, which mentions these cities. The baraita is teaching that the Gamla referred to in the Mishnah is the one in the Galilee, to the exclusion of any Gamla found in other lands, i.e., Judea and Transjordan. Likewise, Gedod is the one in Transjordan, to the exclusion of Gedod in other lands, Judea and the Galilee. In the same vein, Ḥadid, Ono, and Jerusalem are specifically the cities in Judea known by those names. With regard to those other cities mentioned in the Mishnah, e.g., Yodfat, since there are no cities in other lands with similar names, it was not necessary for the tanna of the baraita to state them.

וירושלים מי מיחלט בה? והתניא: עשרה דברים נאמרו בירושלים, אין הבית חלוט בה!

The Talmud asks: And is ownership of a house in Jerusalem transferred in perpetuity to the buyer after one year, in the manner of houses of walled cities? But isn’t it taught in a baraita: 10 matters were stated with regard to Jerusalem, one of which is that ownership of a house situated in Jerusalem is not transferred in perpetuity one year after its sale?