This short paragraph gives 1) a profound Christology and 2) an apologetic against Judaism. Jesus alone can be invested with regal authority because Jesus alone fulfills all the Messianic prophecies.
This sermon untangles the controversies over the prophecy of Jesus being from Nazareth, the prophetic significance of being a Nazarene, the connection to all the passages describing the coming Messiah as "the branch," and more.