1)
Why does it say v'Efer v'Yish'i?"?
1.
Radak: The prefix in v'Efer is extra, like "v'Ayah v'Anah."
2)
What is the significance of seven Rosh Batei Avos?
1.
Malbim: They correspond to the seven Mishpechos of Bnei Machir (Bamidbar 26:29-32).
