Radak: Between Gil'ad and Eretz Yisrael, initially it was not within Eretz Yisrael. Even though it belonged to Yisrael, it was not part from Eretz Kena'an; the Yarden was in between.

Malbim: Initially, the east border was from Chatzer Einan to the Yarden, and to Yam ha'Melach. Ever ha'Yarden was added after they conquered Sichon and Og. Now will be added in the north corner the strip between Chavran and Damesek, and the strip in the northeast corner between Damesek and Gil'ad.

Rashi: This is the east border of Eretz Kena'an. Ever ha'Yarden is not within these borders, only Eretz Kena'an is. Also the borders delineated in the Torah, Ever ha'Yarden is not in them. Our verse teaches that the eastern border is between Chavran and Damesek in the northeast corner, and Gil'ad and Eretz Yisrael east of the Yarden.

Rashi: The Yarden is the eastern border, from the border in the north corner (Chatzer Einan), which is explicit above, until ha'Yam ha'Kadmoni, i.e. Yam ha'Melach ¹ in the southeast corner. You will measure the eastern border [between them]. So it says in the Torah ? "v'Hayu Sotze'osav Yam ha'Melach" (Bamidbar 34:12), in the south corner.

Rashi: This is the southern side.

Malbim: In the east they will have an inheritance without limit. They measured 75 Mil for each Shevet only regarding width [north to south]. The length to the east will constantly increase, as the Shevet increases in population.