1)
Why does it say "u'Ntatim"?
1.
Radak, Malbim: This is like [a tree] planted - it does not budge from its place. I.e. they will not be exiled from their land again, for they will always serve Hashem and do His will.
2)
Why does it say "Amar Hashem Elokecha"?
1.
Radak: So Hashem said to the Navi.
