Here it says "v'Yatza Nachal Mitzrayim." In Bamidbar (34:5, it says "v'Nasav"!
Malbim: Here it says v'Yatza, for the border juts out to include Nachal Mitzrayim. In Bamidbar it says v'Nasav, for the border curves and forms a corner.
What is the meaning of "v'Hayu Totz'os ha'Gevul"?
Rashi: The end of the border [was the Yam ha'Gadol. Yehudah spanned the entire southern border of Eretz Yisrael from east to west.]
Why does it say "Lachem"? The 'narrator' is describing the border. No one is talking to Bnei Yehudah!
Radak: The border will be for them like the Torah says [about the border of Eretz Yisrael] "v'Hayah Lachem Gevul Negev" (Bamidbar 34:3).