מלכים ב, פרק כ׳, פסוק י״ז

A grave prophecy points toward a future era when Babylon will rise as a global power. During that time, the Babylonians will return to plunder the very royal treasures that Hezekiah had willingly displayed to their messengers. The prophet warns of days to come when all the wealth of the kingdom will be carried away. This includes not only the current riches but also the vast abundance carefully stored away by previous generations in the royal treasuries. Every piece of this wealth is destined to be taken directly to Babylon [מצודת דוד, ביאור שטיינזלץ].

The severe warning that absolutely nothing will remain in the royal palace [מצודת דוד] operates on a strict principle of measure for measure. Hezekiah had previously acted with pride, boasting to the Babylonian envoys that there was not a single item in his storehouses that he had failed to show them. As a direct consequence of this display, the punishment dictates that from those exact same treasuries, not a single item will be left behind [רש״י].