Ezekiel 21:26 - Matthew Poole's English Annotations on the Holy Bible

Either God speaks to the prophet to declare the thing, or to Nebuchadnezzar to do the thing, to take away the diadem, the royal tire of the head, which the king did ordinarily and daily wear. The crown; which was a royal ornament used on solemnities, and more than ordinary occasions; or it may be one thing in doubled expressions of the deposing of Zedekiah. The same; the kingdom and crown shall never be what it hath been; as we say of one greatly altered, He is not himself, so here, This shall not be the same; it was great, glorious, and flourishing, but hereafter small, dependent, ignoble, and withering. Exalt him; Jeconiah; it is probable the prophet foretells the advance of this captive king, which came to pass in the 37th year of Jeconiah's captivity, in the first year of Merodach, 2 Kings 25:27-29 Jeremiah 52:31, who exalted his seat above all the captive kings in Babylon. That is low; now in captivity in Babylon. Abase him; Zedekiah, That is high; not now on the throne of Judah, strengthened with the confederacy of Egypt, on which he relieth, and exalteth himself, and bears himself high against the prophet, the king of Babylon, and, which is most insolent, against the God of heaven.