Jer 51:47

“As Babylon hath caused the slain of Israel,.... In Jerusalem, when that city was taken the Chaldeans, and destroyed: so at Babylon shall all the slain of all the earth; or "land"; that is, the land of Chaldea; the inhabitants of which fled to Babylon upon the invasion of the Medes and Persians, both for their own safety, and the defence of that city; and where, being slain, they fell; and this was a just retaliation of them for what they had done to Israel. These words may be considered, as they are by some, as the song of the inhabitants of heaven and earth, observing and applauding the justice and equity of divine Providence in this affair; see Rev 13:7.”

“GROTIUS translates, "Because then (namely, on the third year) the time shall have come that," &c. confounded--at seeing their gods powerless to help them. her slain--in retribution for "Israel's slain" (Jer 51:49) who fell by her hand. GROTIUS translates, "her dancers," as in Jdg 21:21, Jdg 21:23; Sa1 18:6, the same Hebrew word is translated, alluding to the dancing revelry of the festival during which Cyrus took Babylon.”

“Therefore, viz., because what has been stated above will happen, or because the events mentioned in Jer 51:46 are harbingers of the judgment on Babylon, - therefore days are coming when God shall execute judgment on the idols of Babylon, and dry up the land (Note: Keil has here misread the Hebrew text, which runs כּל־ארצהּ תּבּושׁ. The verb does not come from יבשׁ, to become dry, but from בּושׁ, to be ashamed; hence the correct rendering is, "all her land shall be ashamed," not "shall be dried up." - Tr.) (cf. Jer 51:43), and all her slain ones, i.e., all her inhabitants shall fall down, slain in the midst of her. לכן הנּה ימים בּאים, "Therefore, behold, days are coming," is a formula very frequently found in Jeremiah; cf. Jer 7:32; Jer 16:14; Jer 19:6; Jer 23:7, etc.”