What does Luke 20:44 mean?

While Jesus teaches on the Temple Mount, various groups of religious leaders attempt to discredit His authority and His teaching. Each attempt fails miserably. Once they all admit defeat, Jesus presents His own riddle regarding Psalm 110:1. Scripture says that the Christ will be a descendant of David: his "son" (2 Samuel 7:12–13). So why does David call this same figure "Lord" (Luke 20:41–43)? David is implying that the Christ must be greater than himself.

There's an interesting application in Jesus' discussion. At that time, the Jews understood the Messiah to be a military leader who would rescue the people from Roman rule and make Israel independent again. David fits this image as he spent most of his life protecting the Israelites from the Philistines and other peoples. David's "son" could be expected to do likewise. But Jesus points out the Messiah is greater than this Davidic representation.

In the New Testament, speakers and writers often used part of an Old Testament passage to represent a larger part, much like how we might quote a line from a movie to infer the tone of the scene. Jesus' emphasis is on Psalm 110:1, wherein David recognizes an authority besides YHWH. In Psalm 110:4, however, YHWH identifies this figure as "a priest forever after the order of Melchizedek." The Messiah is more than a warrior-king; he is a priest-king. The Jews had no priest-kings; priests were from the tribe of Levi and kings were from the tribe of Judah.

And yet, the Old Testament mentions one priest-king: Melchizedek (Genesis 14:18–20). Abraham tithed to Melchizedek, thereby submitting all his descendants, including the Davidic line of kings and the Levitical priesthood, to this priest-king (Hebrews 7:4–10). Psalm 110:4 identifies David's authority as above even Abraham and his priesthood above the descendants of Aaron.

Hebrews explains why the Messiah must be greater than the Levitical priests. The Levitical priests are fallen and even the most pious cannot offer sufficient sacrifices for the people's sins. Only a "high priest, holy, innocent, unstained, separated from sinners, and exalted above the heavens" can perform the sacrifices we need (Hebrews 7:26). Only David's adōni (Psalm 110:1) and Adōnai (Psalm 110:5) can be king and priest; only He can save the people politically and spiritually (Hebrews 7).

Jesus isn't just showing His theological prowess at the expense of the Pharisees. He's foreshadowing the meaning of His death.