1)
Why does the Torah mention the crossing of the River Yarden here?
1.
Rashi: To inform Yisrael that the miracles of the Yarden will serve as a sign that they will take possession of Eretz Yisrael. 1
1
See Sifsei Chachamim.
2)
What are the implications of the otherwise superfluous) phrase "Viyerishtem osah Viyeshavtem bah"?
1.
Kidushin, 27a: It implies that Yisrael will inherit (take ownership of) the land by dwelling in it - to teach us that one acquires land by means of a Chazakah - doing something to improve it that only an owner would do. 1
2.
Sifri: It implies that on the merit of taking possession of the land, they will dwell in it. 2
