ירמיהו, פרק כ״ז, פסוק ז׳

A clear historical boundary is set for the dominance of the Babylonian Empire, marking a predetermined end to its vast power. The rule of this mighty empire is destined to last for exactly three generations. The timeline precisely traces the dynasty of Nebuchadnezzar, extending through his son, Evil-merodach, and concluding with his grandson, Belshazzar.

The surrounding nations will remain under Babylonian control only until the empire's own time of ruin arrives. This downfall takes place during the era of Darius the Mede and Cyrus, who ultimately conquer the empire and kill Belshazzar [רש״י, מצודת דוד]. The collapse of Babylon operates on a strict principle of exact justice. Just as a time of destruction came for all the various lands and kingdoms that Nebuchadnezzar previously conquered, a time will inevitably arrive for his own land to face the exact same fate [מצודת דוד].

Once these three generations of immense power and authority run their course, the global reality will completely flip. In a dramatic reversal of fortune following Babylon's collapse, many other nations and great kings will rise up to rule over and enslave the former Babylonian Empire itself [ביאור שטיינזלץ].