The Messiah would be greater than David
Before we encounter him in Psalm 110, Melchizedek appears one other time in Genesis 14. There, Abraham (then called Abram) encounters this somewhat mysterious figure. One noteworthy thing about Melchizedek is that he is both a king and a priest (Genesis 14:18). Israelites could not be both; priests were descended from Levi and kings were descended from Judah. But Melchizedek is not an Israelite, and he combined both offices in one person.
In the Gospels, we find Jesus posing a question about the Messiah and his descent from David:
Now while the Pharisees were gathered together, Jesus asked them a question, saying, “What do you think about the Christ [Messiah]? Whose son is he?” They said to him, “The son of David.” He said to them, “How is it then that David, in the Spirit, calls him Lord, saying, ‘The Lord said to my Lord, “Sit at my right hand, until I put your enemies under your feet”’? If then David calls him Lord, how is he his son?” And no one was able to answer him a word, nor from that day did anyone dare to ask him any more questions.
Undoubtedly, the topic of the Messiah was a very live issue in Jesus’ day. There had already been messianic pretenders, and chafing as they were under the yoke of Rome, many people would have been eager to see a Messiah come to destroy their despised overlord. So it was quite natural for Jesus to ask a group of Pharisees about their views on the Messiah. Asked “whose son is he?” they replied with the traditional expectation: he is David’s descendant.
Rabbinic argumentation often centered on resolving two apparently contradictory Bible passages. Here, Jesus does something similar. From a multitude of passages we know that the Messiah had to be the son (that is, a descendant) of David. In that case, how can David address him as “Lord”? How can the Messiah be David’s son and at the same time his Lord? Jesus does not spell out the resolution but leaves his listeners to figure it out for themselves; the implication is that although he is indeed David’s son, he is also something much more.
At this point, Jesus quotes from Psalm 110, which happens to be the Old Testament passage that is quoted more than any other in the New.
The messianic nature of Psalm 110 can be seen in the fact that it comes right in the middle of Psalms 107-113. Psalms 107-109 offer prayers and hope for redemption, while Psalms 111-113 offer praise for redemption. Psalm 110 falls in the middle, highlighting the Redeemer, or in other words, the hoped-for Messiah. This individual is, based on the wording of the Psalm, a figure greater than David, who refers to him as “my Lord” – yet as we know from elsewhere, at the same time, he is David’s son. The implication, which was fully revealed at the coming of Jesus, was that the Messiah was both human and yet more than merely human: God incarnate.
R. Yudan said in the name of R. Hama: In the time to come when the Holy One, blessed be He, seats the Lord Messiah at His right hand, as is said The Lord saith unto my lord: “Sit thou at My right hand” and seats Abraham at His left, Abraham’s face will pale, and he will say to the Lord: “My son’s son sits at the right, and I at the left!”
In other words, the Messiah will receive greater glory, sitting at God’s right hand, than his ancestor Abraham, who sits in the position of lesser honor on the left. The Messiah, though descended from Abraham, nevertheless receives greater glory. This is reminiscent of Psalm 110 in which the Messiah, descended from David, nevertheless receives greater glory because he is David’s Lord.
In Acts 2:34-36, Peter addresses a crowd of his fellow Jews at the holiday of Shavuot (Pentecost). After speaking of Jesus’ resurrection by quoting from Psalm 16 (see comments on that passage), he also points out that Psalm 110 speaks of someone greater than David:
“For David did not ascend into the heavens, but he himself says, ‘The Lord said to my Lord, “Sit at my right hand, until I make your enemies your footstool.”’ Let all the house of Israel therefore know for certain that God has made him both Lord and Messiah, this Jesus whom you crucified.”
And finally, we have this passage from Hebrews 5:1-10:
For every high priest chosen from among men is appointed to act on behalf of men in relation to God, to offer gifts and sacrifices for sins. He can deal gently with the ignorant and wayward, since he himself is beset with weakness. Because of this he is obligated to offer sacrifice for his own sins just as he does for those of the people. And no one takes this honor for himself, but only when called by God, just as Aaron was.
So also Christ did not exalt himself to be made a high priest, but was appointed by Him who said to him, “You are my Son, today I have begotten you”; as he says also in another place, “You are a priest forever, after the order of Melchizedek.” In the days of his flesh, Jesus offered up prayers and supplications, with loud cries and tears, to him who was able to save him from death, and he was heard because of his reverence. Although he was a son, he learned obedience through what he suffered. And being made perfect, he became the source of eternal salvation to all who obey him, being designated by God a high priest after the order of Melchizedek.
Here the author of Hebrews quotes both Psalm 2 and Psalm 110 to show that Jesus was both king and priest. As king, he rules; as priest, he intercedes for us before God the Father. And though Jesus was not descended from Levi, his priesthood is in the model of Melchizedek, the non-Levitical king-priest whom Abraham encountered.
And so Jesus the Messiah is greater than David by virtue of being both human and divine: he is the son of David and also David’s Lord. And by being both our king and priest, a combination not allowed in ancient Israel, he shows yet another way that he is greater than David.