What is "Kefadah"?
Rashi: This is like "Kipadti 1 cha'Oreg Chayai" (Yeshayah 38:12); it is an expression of cutting.
Malbim: Above (23) it said "Ase ha'Ratok", which includes a chain of the causes of evils. Kefadah is the tie of this chain - the rings are tied one to another, an evil to its fellow evil.
Radak: Kefadah is mil'Eil (the penultimate syllable is accented) because it is Samuch to a word of one syllable. Alternatively, it is masculine; the Hei is extra (so the last syllable is not accented).
What Shalom do they seek, and it is not?
Radak: They seek the Shalom that the false Nevi'im promised to them.
Malbim: They will not find Shalom due to the constant afflictions (refer to 7:26:1:3).