Root of Jesse is one of the weirder statements about the nature of Christ. It basically says that Christ comes from a royal lineage, and Christ's coming has been foretold.
What strikes me about this Antiphon is the command, "Come to free us, and do not delay." What I love about the prophetic literature is God's people holding God to God's promises. This feels particularly pertinent today.
O Root of Jesse, free us and do not delay. Be a leader of peace in a world of violence. O Radix Jesse, O Root of Jesse, come.