1)
Why does it say "ha'Sam Gevulech Shalom"?
1.
Radak: And so you will be blessed outside, with Shalom and fruits of their land.
2.
Malbim: The enemy will not enter your gates. This corresponds to "He strengthened the bolts of your gates" (13).
2)
What are "Chelev Chitim"?
1.
Rashi: They are the best wheat [kernels]; they are fat. Malbim - this corresponds to "He blessed your children inside you" (13).