Ezekiel 17 - the birth of the Christ reign

King Zedekiah made an alliance with Babylon but he betrayed such alliance, seeking refuge in Egypt. We read:

16-18 “‘As sure as I am the living God, this king who broke his pledge of loyalty and his covenant will die in that country, in Babylon. Pharaoh with his big army—all those soldiers!—won’t lift a finger to fight for him when Babylon sets siege to the city and kills everyone inside. Because he broke his word and broke the covenant, even though he gave his solemn promise, because he went ahead and did all these things anyway, he won’t escape.

19-21 “‘Therefore, God, the Master, says, As sure as I am the living God, because the king despised my oath and broke my covenant, I’ll bring the consequences crashing down on his head. I’ll send out a search party and catch him. I’ll take him to Babylon and have him brought to trial because of his total disregard for me. All his elite soldiers, along with the rest of the army, will be killed in battle, and whoever is left will be scattered to the four winds. Then you’ll realize that I, God, have spoken.

King Zedekiah was the last king of Davidic dynasty in Judah. Jeremiah prophesied that he should surrender to the Babylonians and not seek refuge in Egypt, but he didn't listen to Jeremiah. Ezekiel is in Babylon prophesying the same as Jeremiah. We know that we didn't have any king of Davidic dynasty ruling over Israel or Judah after Zedekiah.

22-24 “‘God, the Master, says, I personally will take a shoot from the top of the towering cedar, a cutting from the crown of the tree, and plant it on a high and towering mountain, on the high mountain of Israel. It will grow, putting out branches and fruit—a majestic cedar. Birds of every sort and kind will live under it. They’ll build nests in the shade of its branches. All the trees of the field will recognize that I, God, made the great tree small and the small tree great, made the green tree turn dry and the dry tree sprout green branches. I, God, said it—and I did it.’

The commentary "Cambridge Bible for Schools and Colleges" says:

The attempt of the king of Babylon to set up a kingdom in Israel miscarried; he who set up the kingdom took it away. The shoot planted by him was smitten by the east wind and withered. But Jehovah himself will plant a shoot of the high cedar, the Davidic house, on a high mountain that all nations may see it (Isaiah 2:2; Isaiah 11:10), even on the height of the mountain land of Israel, and it shall become a great cedar, so that all the fowls of heaven shall lodge in the branches of it. This kingdom shall be imposing and universal, and all peoples shall find protection under it. And then shall it be known that Jehovah is king among the nations, that kingdoms are in his hand, to set one up and pull another down; that he can make the green tree wither and the dry tree blossom and bear fruit.