The horn — Jehoiakim, who was then advanced by Evil — Merodach. The opening of the mouth — Thou shalt have liberty, to open thy mouth in comforting the good among them, and to give praise to God.
Related Commentaries of Ezekiel 29:21
Ezekiel 29:21
21 In that day will I cause the horn of the house of Israel to bud forth, and I will give thee the opening of the mouth in the midst of them; and they shall know that I am the LORD.