Latin: O Radix Jesse, qui stas in signum populorum, super quem continebunt reges os suum, quem gentes deprecabuntur: veni ad liberandum nos, iam noli tardare.
English: O Root of Jesse, that stands for an ensign of the people, before whom the kings keep silence and unto whom the Gentiles shall make supplication: come to deliver us, and tarry not.
Relevant verse of Veni, Veni Emmanuel:
O come, O Rod of Jesse, free Thine own from Satan’s tyranny;
From depths of hell Thy people save; and give them victory o’er the grave.