Charles Ellicott Commentary Ezekiel 29:21

"In that day will I cause a horn to bud forth unto the house of Israel, and I will give thee the opening of the mouth in the midst of them; and they shall know that I am Jehovah." — Ezekiel 29:21 (ASV)

In that day. —The tenses here change to the future, indicating that if the conquest of Egypt had already taken place, its consequences to Israel were to be only gradually developed. These consequences were primarily the conviction of the futility of trust in any earthly aid, and therefore a turning to their neglected God, and, as a result of this, the giving up of their long-cherished idolatries. The prophet speaks of this as only in its initial stage, but looking forward to its further development, under the figure of making a horn to bud forth, that is, to sprout or grow. (Compare to Psalms 132:17.) Israel’s reviving prosperity should date from the destruction of its trust in earthly aid.

The opening of the mouth. —This is elsewhere (Ezekiel 24:27) promised to the prophet as a consequence of the fall of Jerusalem, of which he had heard (Ezekiel 33:21–22) more than fourteen years before. There is no recorded prophecy of Ezekiel’s of later date; the expression must therefore be understood of those encouraging and helpful instructions of the prophet, as the people improved under the discipline of the captivity, which it was not considered fitting to preserve in a permanent record.