When will he see the chariot?
Rashi: It will be when he prays for it.
Radak: While he is listening, he will see the chariot come close to the city.
Why does it say "Naflah" twice?
Targum Yonasan: It fell, and it will fall in the future. Rashi (from Seder Olam 28) - first it fell via Paras and Madai (Daryavesh), and the next year, via Shamayim. "It was the glorious kingdom; it will be like the overturn of Sedom" (13:19). Radak - that Bavel will never be settled again, like I explained above (refer to 13:19:4:1).
Radak: It is to strengthen the matter.
Malbim: Initially, the lookout thought, what will one chariot do?! Will they destroy Bavel, the glorious kingdom?! However, amidst screaming, he recognized that Bavel already fell; they killed the king, and rebelled [against] Bavel. He said, indeed, Bavel fell. It fell suddenly; no one sensed that it will happen until it did. See, it is Hashem's word!
Who broke [the idols]?
Radak: The breaker. (The verse does not say who did so.)
