Did Bavel say so?
Rashi: They thought in their hearts.
What is the significance of "l'Olam Ehyeh Gevares"?
Rashi: Punishment will not come upon me.
Malbim: You think that your kingship is due to your strength. Really, your authority is temporary, due to the sin of Am Hashem. Refer to 47:7:3:2.
What did Bavel not put to heart?
Rashi: These punishments that will come upon them.
Malbim: (Bavel is compared to a base man authorized to chastise a son who rebelled against his esteemed father.) He should have realized that his authority will last only as long as the father is angry at his son. When he makes a heavy yoke on the son, the father will see his affliction and have mercy on him, and remove the base man's authority.
What end did she not remember?
Rashi: What will be the end (punishment) for the evil that she did.
Radak #1: Her great pride will be lowered.
Radak #2: The end of Yerushalayim, which was mistress, and fell into your hand.
Malbim: Hashem will demand from you [retribution] for blood [that you spilled].
