1)
What is the significance of "Ein Shalom Amar Hashem la'Resha'im"?
1.
Shabbos 152b: This refers to the bodies of Resha'im [after death].
2.
Kesuvos 104a: When a Rasha leaves this world, three groups of damaging angels greet him. One says this verse to him, another says "in sadness you will lie down"; and the third says, "Descend and lie with the uncircumcised."
3.
Malbim: You need not fear the Kasdim any more, for they will never have Shalom.
2)
Which Resha'im are discussed?
1.
Rashi: Nebuchadnetzar and his seed.
2.
Radak, Malbim: Anshei Bavel.