1)
What is the meaning of "k'Mar'isam va'Yisba'u"?
1.
Rashi: When they came to the land of their pasture - then they were satiated. Radak - this is Eretz Yisrael.
2)
What do we learn from "Sav'u va'Yaram Libam"?
1.
Rashi: This is like "va'Yaram ba'Mateh" (Shemos 7:20) - lifting something else. Here, [their heart] lifted itself. Radak - then they forgot Me, like the Torah says will happen - "Pen Tochal v'Savata u'Vatim Tovim Tivneh v'Yashavta; u'Vkarcha v'Tzonecha Yirbeyun v'Kesef v'Zahav Yirbeh Lach; v'Ram Levavecha v'Shachachta Es Hashem Elokecha" (Devarim 8:12-14), "va'Yishman Yeshurun va'Yiv'at" (ibid. 32:15).