1)
Having promised Eretz Yisrael to Yaakov (see 28:13), why did Hashem see fit to repeat it here? And why does it repeat "Lecha Etnenah... Eten"?
1.
Ramban #1: Here Hashem equated Yaakov to Avraham and Yitzchak, who were promised Eretz Yisrael with a Shevu'ah. 1 Above, Hashem had promised it to Yaakov without a Shevu'ah. 2
2.
Ramban #2: The repetition of the prophecy is considered a Shevu'ah.
3.
Oznayim la'Torah #1: Hashem was appointing Yaakov a co-owner of the land alongside Avraham and Yitzchak; all would bequeath the land to their children.
4.
Oznayim la'Torah #2: He was promising the land to Yaakov, to preclude Esav.
