The Last Supper and the Passion Narrative, Jesus Is Going to Be a Priest King

The psalm was actually used by the priestly family that went back to the Maccabees. Caiaphas would have been in that line. The Hasmonean kings were priests and they would use Psalm 110. But what Jesus is doing is now quoting the psalm, reminding them of its Davidic connections. He's pointing to the fact that the son of David would be greater than David himself.