What is the meaning of "v'Sa'ar"?
Rashi: It is to turn in a circle, like "uva'Mechugah Yesa'arehu" (Yeshayah 44:13).
Rashi citing Targum Yonasan: Va'Yischar (Lev Yitzchak - goes around).
Rashi (3): It juts out or recesses inwards.
Ibn Ezra, Radak (Yeshayah 44:13): You should mark [dye the land so the border will be recognized].
Malbim: It surrounds it on three sides. Here, the [border] line was round and took a strip from Binyamin portion into Yehudah's. The Mizbe'ach was built on that strip.
Lev Yitzchak: Some texts of Targum Yonasan say v'Sa'ar (just like the text), it is to go straight (like Gra (3)), or to mark (refer to 15:9:1:4).
What is Mayan Mei Nefto'ach?
Radak: This is what Chachamim called Ein Eitam (refer to 13:8:1:1).
To which direction does the border go?
Rashi: It goes to the north and widens until the cities of Har Efron, and envelops Ba'alah on the north.
Why does it say "Hi Kiryas Ye'arim"?
Malbim: There was another Ba'alah in the south (verse 29), it is Balah that was given to Shimon (19:3). This is why Kiryas Ye'arim is called Ba'alei Yehudah (Shmuel 2 6:2).
