But, of the Babylonians, he who spoke of them words of consolation (in the beginning) — (Jeremiah 27:6) "I have given all these lands into the hand of Nevuchadnezzar, king of Bavel, My servant; even the beasts of the field have I given him to serve him" — He reverted to words of retribution — (Ibid. 51:64) "And you shall say: 'Thus shall Bavel sink and it shall not rise because of the evil I am bringing upon her, and she shall grow faint.' Until here the words of Jeremiah." He who (in the beginning) spoke of the Babylonians words of consolation, (in the end) reverted to words of retribution.
Jeremiah's Dual Prophecy of Destruction and Comfort
Sifrei Devarim 342:3