Rashi: This is "Kasdim" according to At-Bash (we exchange the first, second, third... letters of the Aleph Beis with the first, second... letters from the end).

Radak: Perhaps it should say Yoshvei Eretz Kasdim, just the latter two words are omitted. The verse relies on the reader to understand, for Bavel was already mentioned; verses do so in many places. Lev Kamai is like the simple meaning, the heart of My enemies; they dwell in Eretz Kasdim. Yonason translates like this.

Rashi: It is the desire of Melech Pras and Madai, who destroys.

Malbim: The enemy does not intend for his benefit, only to destroy, and not leave a remnant.